Refactor code structure for improved readability and maintainability

Sets submodule.<name>.branch = main so `git submodule update --remote`
resolves each submodule to the tip of main without needing a
per-invocation --branch argument.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>

.github/copilot-instructions.md

@@ -1,16 +1,21 @@
 # Copilot Instructions
 
 > ## ⚠️ Instruction Sync
-> This file (`.github/copilot-instructions.md`) and the Claude Code instructions
-> (`/CLAUDE.md`) are **two views of the same project rules and must stay in sync**.
-> Whenever you change one, make the equivalent change in the other in the same
-> commit. `CLAUDE.md` may add tool-specific workflow notes, but the shared
+> This file (`.github/copilot-instructions.md`), the Claude Code instructions
+> (`/CLAUDE.md`), and the Codex instructions (`/CODEX.md`) are **three views of
+> the same project rules and must stay in sync**.
+> Whenever you change one, make the equivalent change in the other two in the same
+> commit. `CLAUDE.md` and `CODEX.md` may add tool-specific workflow notes, but the shared
 > project facts (architecture, coding standards, configuration, libraries,
 > secrets, observability) must match.
 
 ## Project Overview
 - **Fuchs Intranet** is an ASP.NET Core (.NET 10) web application — the intranet IS the entire website, served from `/`.
 - Routes: `/{fn?}/{id?}/{code?}` → `IntranetController.Index`; `/do/{fn?}/{id?}/{code?}` → `IntranetController.Do`.
+- Build app: `dotnet build Fuchs/Fuchs.csproj -c Debug`. Build all: `dotnet build Fuchs_Intranet.slnx -c Debug`.
+- Frontend assets are source-built: run the gulp tasks in `Fuchs/` (`npx gulp min`, or `npx gulp all` when copied/static assets also need refreshing) whenever JS or SCSS/CSS sources change. The generated files under `Fuchs/wwwroot/web/` are what the app serves.
+- Test: `dotnet test Fuchs.Tests/Fuchs.Tests.csproj -c Debug`.
+- Submodules include the OCORE projects and `eRechnungLib` (ZUGFeRD/Factur-X + XRechnung generation) — invoices are moving to eRechnung output.
 - Project structure (relative to `Fuchs/`):
   - `Controllers/` — `IntranetController` partials (no area)
   - `code/` — business logic, PDF, email, widgets, data models
@@ -42,8 +47,8 @@
 
 ## Services & Dependency Injection
 - Business logic lives in **DI-registered services** under `Fuchs/Services/` behind interfaces; inject them into `IntranetController` (constructor injection). Do **not** reintroduce static God-classes or pass the whole controller into helpers.
-  - `IComService` (email/SMS via ProcessWeb Mailer API, attachments sent inline as base64; honors the `Fuchs:Email:OverrideRecipient` dev safety net — see Configuration), `IPdfService` (MigraDoc render), `IInvoiceService`, `IReminderService`, `IReportService` (SQL report engine via `FuchsVisualization`), `IWidgetService`, `IBankingService`, `IMfrClientFactory`.
-  - Lifetimes: stateless services (`IPdfService`, `IBankingService`, `IMfrClientFactory`) are singletons; request-scoped DB services (`IInvoiceService`, `IReminderService`, `IReportService`, `IWidgetService`, `IComService`) are scoped. Register in `Program.cs`.
+  - `IComService` (email/SMS via ProcessWeb Mailer API, attachments sent inline as base64; honors the `Fuchs:Email:OverrideRecipient` dev safety net — see Configuration), `IPdfService` (MigraDoc render), `IInvoiceService`, `IReminderService`, `IReportService` (SQL report engine via `FuchsVisualization`), `IWidgetService`, `IBankingService`, `IMfrClientFactory`, `ISystemStatusService` (Admin module diagnostics: config snapshot + DB/Key Vault/blob/MFR connectivity probes + test-email; restricted to `fds_sys` > 4).
+  - Lifetimes: stateless services (`IPdfService`, `IBankingService`, `IMfrClientFactory`) are singletons; request-scoped DB services (`IInvoiceService`, `IReminderService`, `IReportService`, `IWidgetService`, `IComService`, `ISystemStatusService`) are scoped. Register in `Program.cs`.
 - `FdsInvoiceData` / `FdsReminderData` are **pure data holders** (parse + properties). Loading, persistence and PDF generation belong in the services — never `Task.Run(...).Wait()` sync-over-async.
 - Data access stays SQL-first via OCORE helpers (`getSQLDataSet_async`, `setSQLValue_async`) + stored procedures; no EF Core.
 
@@ -74,6 +79,11 @@
   - Name tests `MethodName_Scenario_ExpectedResult`.
   - DB-bound paths that can't be unit-tested should at least have their pure logic covered.
 
+## Decisions & Concepts
+- `Fuchs/Docs/Decisions/` holds immutable ADRs (architecture decision records); `Fuchs/Docs/Concepts/` holds living design write-ups kept in sync with the code. Each folder's `README.md` explains the format, naming, and required YAML frontmatter — **read it before creating or editing entries there.**
+- **Accepted decisions must be followed.** Before working in an area covered by a decision, read it and conform to it; don't silently deviate. Every file's YAML frontmatter has an `applyTo` glob — scan frontmatter across the folder first (cheap) and only read the full body of entries relevant to the files you're touching.
+- **Capture new decisions and concepts as they happen.** When a non-obvious architectural or cross-cutting choice gets settled (by the user or in the course of implementation), add a decision in `Docs/Decisions` in the same change, and create/update the matching concept doc in `Docs/Concepts` if the subsystem's design is otherwise non-obvious from the code.
+
 ## Azure Key Vault — Secret Naming
 - Secret names must satisfy the pattern `^[0-9a-zA-Z-]+$` (alphanumerics and hyphens only; no underscores, dots, or spaces).
 - Hierarchy levels are separated by `--` (double hyphen), which maps to `:` in `IConfiguration`.

.gitignore

@@ -7,6 +7,9 @@
 bin/
 obj/
 
+# Scratch / build-verification output
+/tmp/
+
 # SSDT / SQL database project caches (regenerated)
 *.dbmdl
 *.jfm

.gitmodules

@@ -1,12 +1,20 @@
 [submodule "OCORE"]
 	path = OCORE
 	url = https://git.processweb.de/Stefan/OCORE.git
+	branch = main
 [submodule "OCORE_web"]
 	path = OCORE_web
 	url = https://git.processweb.de/Stefan/OCORE_web.git
+	branch = main
 [submodule "OCORE_web_pdf"]
 	path = OCORE_web_pdf
 	url = https://git.processweb.de/Stefan/OCORE_web_pdf.git
+	branch = main
 [submodule "OCORE_Charting"]
 	path = OCORE_Charting
 	url = https://git.processweb.de/Stefan/OCORE_Charting.git
+	branch = main
+[submodule "eRechnungLib"]
+	path = eRechnungLib
+	url = https://git.processweb.de/ProcessWeb_Tools/eRechnungLib.git
+	branch = main

.vscode/launch.json

@@ -0,0 +1,28 @@
+{
+    "version": "0.2.0",
+    "configurations": [
+        {
+            "name": "Fuchs: Debug ASP.NET Core",
+            "type": "coreclr",
+            "request": "launch",
+            "preLaunchTask": "build Fuchs",
+            "program": "${workspaceFolder}/Fuchs/bin/Debug/net10.0/Fuchs.dll",
+            "args": [],
+            "cwd": "${workspaceFolder}/Fuchs",
+            "stopAtEntry": false,
+            "justMyCode": true,
+            "serverReadyAction": {
+                "action": "openExternally",
+                "pattern": "\\bNow listening on:\\s+(https?://\\S+)",
+                "uriFormat": "%s"
+            },
+            "env": {
+                "ASPNETCORE_ENVIRONMENT": "Development",
+                "ASPNETCORE_URLS": "https://localhost:63661;http://localhost:63662"
+            },
+            "sourceFileMap": {
+                "/Views": "${workspaceFolder}/Fuchs/Views"
+            }
+        }
+    ]
+}

.vscode/settings.json

@@ -0,0 +1,9 @@
+{
+    "chat.tools.terminal.autoApprove": {
+        "dotnet run": true,
+        "dotnet test": true,
+        "dotnet build": true,
+        "npx gulp": true,
+        "ForEach-Object": true
+    }
+}

.vscode/tasks.json

@@ -0,0 +1,129 @@
+{
+    "version": "2.0.0",
+    "tasks": [
+        {
+            "label": "build Fuchs",
+            "type": "process",
+            "command": "dotnet",
+            "args": [
+                "build",
+                "${workspaceFolder}/Fuchs/Fuchs.csproj",
+                "--configuration",
+                "Debug",
+                "/p:RestoreIgnoreFailedSources=true",
+                "/p:RestoreConfigFile=${workspaceFolder}/NuGet.config"
+            ],
+            "problemMatcher": "$msCompile",
+            "group": {
+                "kind": "build",
+                "isDefault": true
+            }
+        },
+        {
+            "label": "gulp: all",
+            "type": "shell",
+            "command": "npx",
+            "args": [
+                "gulp",
+                "all"
+            ],
+            "options": {
+                "cwd": "${workspaceFolder}/Fuchs"
+            },
+            "problemMatcher": []
+        },
+        {
+            "label": "gulp: min",
+            "type": "shell",
+            "command": "npx",
+            "args": [
+                "gulp",
+                "min"
+            ],
+            "options": {
+                "cwd": "${workspaceFolder}/Fuchs"
+            },
+            "problemMatcher": [],
+            "group": "build"
+        },
+        {
+            "label": "gulp: copy",
+            "type": "shell",
+            "command": "npx",
+            "args": [
+                "gulp",
+                "copy"
+            ],
+            "options": {
+                "cwd": "${workspaceFolder}/Fuchs"
+            },
+            "problemMatcher": []
+        },
+        {
+            "label": "gulp: min:js",
+            "type": "shell",
+            "command": "npx",
+            "args": [
+                "gulp",
+                "min:js"
+            ],
+            "options": {
+                "cwd": "${workspaceFolder}/Fuchs"
+            },
+            "problemMatcher": []
+        },
+        {
+            "label": "gulp: min:css",
+            "type": "shell",
+            "command": "npx",
+            "args": [
+                "gulp",
+                "min:css"
+            ],
+            "options": {
+                "cwd": "${workspaceFolder}/Fuchs"
+            },
+            "problemMatcher": []
+        },
+        {
+            "label": "gulp: min:scss",
+            "type": "shell",
+            "command": "npx",
+            "args": [
+                "gulp",
+                "min:scss"
+            ],
+            "options": {
+                "cwd": "${workspaceFolder}/Fuchs"
+            },
+            "problemMatcher": []
+        },
+        {
+            "label": "gulp: min:html",
+            "type": "shell",
+            "command": "npx",
+            "args": [
+                "gulp",
+                "min:html"
+            ],
+            "options": {
+                "cwd": "${workspaceFolder}/Fuchs"
+            },
+            "problemMatcher": []
+        },
+        {
+            "label": "gulp: watch",
+            "type": "shell",
+            "command": "npx",
+            "args": [
+                "gulp",
+                "watch"
+            ],
+            "options": {
+                "cwd": "${workspaceFolder}/Fuchs"
+            },
+            "isBackground": true,
+            "problemMatcher": []
+        }
+    ]
+}

CAMTParser/CamtParser.cs

@@ -52,33 +52,48 @@ public sealed class CamtParser
     /// <summary>
     /// Parses all CAMT XML files found inside a ZIP archive and returns
     /// the combined list of statements. Non-XML entries and malformed XML
-    /// entries are silently skipped.  Used for camt.052 deliveries where the
+    /// entries are skipped. Used for camt.052 deliveries where the
     /// bank wraps one or more intraday reports in a single ZIP file.
     /// </summary>
-    public List<CamtStatement> ParseZip(byte[] bytes)
-    {
-        using var ms = new MemoryStream(bytes);
-        return ParseZip(ms);
-    }
+    public List<CamtStatement> ParseZip(byte[] bytes) => ParseZip(bytes, out _);
 
     /// <inheritdoc cref="ParseZip(byte[])"/>
-    public List<CamtStatement> ParseZip(Stream stream)
+    public List<CamtStatement> ParseZip(Stream stream) => ParseZip(stream, out _);
+
+    /// <summary>
+    /// Same as <see cref="ParseZip(byte[])"/>, but also reports which entries were
+    /// skipped and why (non-.xml name, non-XML content, malformed XML), so callers
+    /// can log a reason instead of silently losing part of a delivery.
+    /// </summary>
+    public List<CamtStatement> ParseZip(byte[] bytes, out List<string> skippedEntries)
+    {
+        using var ms = new MemoryStream(bytes);
+        return ParseZip(ms, out skippedEntries);
+    }
+
+    /// <inheritdoc cref="ParseZip(byte[], out List{string})"/>
+    public List<CamtStatement> ParseZip(Stream stream, out List<string> skippedEntries)
     {
         var result = new List<CamtStatement>();
+        var skipped = new List<string>();
         using var archive = new ZipArchive(stream, ZipArchiveMode.Read, leaveOpen: true);
         foreach (var entry in archive.Entries)
         {
             if (!entry.Name.EndsWith(".xml", StringComparison.OrdinalIgnoreCase))
-                continue;
+                continue; // non-XML entries (e.g. checksums, manifests) are expected, not worth reporting
             using var entryStream = entry.Open();
             using var buffer = new MemoryStream();
             entryStream.CopyTo(buffer);
             var entryBytes = buffer.ToArray();
             if (!LooksLikeXml(entryBytes))
+            {
+                skipped.Add($"{entry.Name}: not XML content");
                 continue;
-            try { result.AddRange(Parse(entryBytes)); }
-            catch (FormatException) { /* skip malformed XML entries */ }
             }
+            try { result.AddRange(Parse(entryBytes)); }
+            catch (FormatException ex) { skipped.Add($"{entry.Name}: {ex.Message}"); }
+        }
+        skippedEntries = skipped;
         return result;
     }
 

CLAUDE.md

@@ -1,20 +1,21 @@
 # CLAUDE.md — Project instructions for Claude Code
 
 > ## ⚠️ Instruction Sync
-> This file and **`.github/copilot-instructions.md`** are two views of the same
-> project rules and **must stay in sync**. When you change a shared rule
+> This file, **`CODEX.md`**, and **`.github/copilot-instructions.md`** are three
+> views of the same project rules and **must stay in sync**. When you change a shared rule
 > (architecture, coding standards, configuration, libraries, secrets,
-> observability, testing), make the equivalent change in **both files in the
+> observability, testing), make the equivalent change in **all three files in the
 > same commit**. This file may add Claude Code / workflow specifics; the shared
-> project facts must match `copilot-instructions.md`.
+> project facts must match `CODEX.md` and `copilot-instructions.md`.
 
 ## Project Overview
 - **Fuchs Intranet** — ASP.NET Core (**.NET 10**) web app; the intranet IS the whole website, served from `/`.
 - Routes: `/{fn?}/{id?}/{code?}` → `IntranetController.Index`; `/do/{fn?}/{id?}/{code?}` → `IntranetController.Do` (dispatches by `fn` to `Do_Process_*`).
-- Solution `Fuchs_Intranet.slnx`. Key projects: `Fuchs` (web), `Fuchs_DataService` (MFR sync worker), `MFR_RESTClient`, `CAMTParser`, `Fuchs.Tests`, and the OCORE submodules (`OCORE`, `OCORE_web`, `OCORE_web_pdf`, `OCORE_Charting`). `MT940Parser` is an external referenced project.
+- Solution `Fuchs_Intranet.slnx`. Key projects: `Fuchs` (web), `Fuchs_DataService` (MFR sync worker), `MFR_RESTClient`, `CAMTParser`, `Fuchs.Tests`, and the OCORE submodules (`OCORE`, `OCORE_web`, `OCORE_web_pdf`, `OCORE_Charting`). `eRechnungLib` is a submodule (ZUGFeRD/Factur-X + XRechnung generation) — invoices are moving to eRechnung output. `MT940Parser` is an external referenced project.
 
 ## Build & Test (workflow)
 - Build app: `dotnet build Fuchs/Fuchs.csproj -c Debug`. Build all: `dotnet build Fuchs_Intranet.slnx -c Debug`.
+- Frontend assets are source-built: run the gulp tasks in `Fuchs/` (`npx gulp min`, or `npx gulp all` when copied/static assets also need refreshing) whenever JS or SCSS/CSS sources change. The generated files under `Fuchs/wwwroot/web/` are what the app serves.
 - Test: `dotnet test Fuchs.Tests/Fuchs.Tests.csproj -c Debug`.
 - Always build **and** run the test suite before committing. The build emits many pre-existing analyzer/platform warnings (CA1416 etc.) — those are expected; only treat `: error` lines as failures.
 - Commit only when asked. Co-author trailer: `Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>`.
@@ -36,7 +37,7 @@
 
 ## Services & Dependency Injection
 - Business logic lives in **DI-registered services** under `Fuchs/Services/` behind interfaces, injected into `IntranetController`. Do not reintroduce static God-classes or pass the controller into helpers.
-- Services: `IComService` (ProcessWeb Mailer API; honors the `Fuchs:Email:OverrideRecipient` dev safety net — see Configuration), `IPdfService`, `IInvoiceService`, `IReminderService`, `IReportService`, `IWidgetService`, `IBankingService`, `IMfrClientFactory`. Stateless ones are singletons; DB/request-scoped ones are scoped (see `Program.cs`).
+- Services: `IComService` (ProcessWeb Mailer API; honors the `Fuchs:Email:OverrideRecipient` dev safety net — see Configuration), `IPdfService`, `IInvoiceService`, `IReminderService`, `IReportService`, `IWidgetService`, `IBankingService`, `IMfrClientFactory`, `ISystemStatusService` (Admin module diagnostics: config snapshot + DB/Key Vault/blob/MFR connectivity probes + test-email; restricted to `fds_sys` > 4). Stateless ones are singletons; DB/request-scoped ones are scoped (see `Program.cs`).
 - `FdsInvoiceData` / `FdsReminderData` are **pure data holders**; load/persist/render belongs in services. No `Task.Run(...).Wait()` sync-over-async.
 - Data access is SQL-first via OCORE helpers + stored procedures (no EF Core).
 
@@ -69,8 +70,15 @@
 ## Secrets (Azure Key Vault)
 - Full naming rules live in `.github/copilot-instructions.md` (kept in sync). In short: names match `^[0-9a-zA-Z-]+$`, hierarchy via `--` (→ `:`), underscores → `-`, app prefix `fuchs`; register new keys in `ManagedSecretKeys` in `appsettings.json`.
 
+## Decisions & Concepts
+- `Fuchs/Docs/Decisions/` holds immutable ADRs (architecture decision records); `Fuchs/Docs/Concepts/` holds living design write-ups kept in sync with the code. Each folder's `README.md` explains the format, naming, and required YAML frontmatter — **read it before creating or editing entries there.**
+- **Accepted decisions must be followed.** Before working in an area covered by a decision, read it and conform to it; don't silently deviate. Every file's YAML frontmatter has an `applyTo` glob — scan frontmatter across the folder first (cheap) and only read the full body of entries relevant to the files you're touching.
+- **Capture new decisions and concepts as they happen.** When a non-obvious architectural or cross-cutting choice gets settled (by the user or in the course of implementation), add a decision in `Docs/Decisions` in the same change, and create/update the matching concept doc in `Docs/Concepts` if the subsystem's design is otherwise non-obvious from the code.
+
 ## Documentation map
 - `Fuchs/Docs/ARCHITECTURE.md` — solution architecture (keep current when structure changes).
 - `Fuchs/Docs/USER_GUIDE.md` — end-user process guide.
+- `Fuchs/Docs/Decisions/` — ADRs; see `Decisions & Concepts` above.
+- `Fuchs/Docs/Concepts/` — living subsystem design docs; see `Decisions & Concepts` above.
 - `MFR_RESTClient/Docs/mfr_interface_description.md` — mfr ERP REST/OData interface contract.
 - `.github/instructions/*.instructions.md` — domain-specific contributor guidance.

CODEX.md

@@ -0,0 +1,84 @@
+# CODEX.md — Project instructions for Codex
+
+> ## Instruction Sync
+> This file, **`CLAUDE.md`**, and **`.github/copilot-instructions.md`** are three
+> views of the same project rules and **must stay in sync**. When you change a shared rule
+> (architecture, coding standards, configuration, libraries, secrets,
+> observability, testing), make the equivalent change in **all three files in the
+> same commit**. This file may add Codex / workflow specifics; the shared
+> project facts must match `CLAUDE.md` and `copilot-instructions.md`.
+
+## Project Overview
+- **Fuchs Intranet** — ASP.NET Core (**.NET 10**) web app; the intranet IS the whole website, served from `/`.
+- Routes: `/{fn?}/{id?}/{code?}` -> `IntranetController.Index`; `/do/{fn?}/{id?}/{code?}` -> `IntranetController.Do` (dispatches by `fn` to `Do_Process_*`).
+- Solution `Fuchs_Intranet.slnx`. Key projects: `Fuchs` (web), `Fuchs_DataService` (MFR sync worker), `MFR_RESTClient`, `CAMTParser`, `Fuchs.Tests`, and the OCORE submodules (`OCORE`, `OCORE_web`, `OCORE_web_pdf`, `OCORE_Charting`). `eRechnungLib` is a submodule (ZUGFeRD/Factur-X + XRechnung generation) — invoices are moving to eRechnung output. `MT940Parser` is an external referenced project.
+
+## Build & Test (workflow)
+- Build app: `dotnet build Fuchs/Fuchs.csproj -c Debug`. Build all: `dotnet build Fuchs_Intranet.slnx -c Debug`.
+- Frontend assets are source-built: run the gulp tasks in `Fuchs/` (`npx gulp min`, or `npx gulp all` when copied/static assets also need refreshing) whenever JS or SCSS/CSS sources change. The generated files under `Fuchs/wwwroot/web/` are what the app serves.
+- Test: `dotnet test Fuchs.Tests/Fuchs.Tests.csproj -c Debug`.
+- Always build **and** run the test suite before committing. The build emits many pre-existing analyzer/platform warnings (CA1416 etc.) — those are expected; only treat `: error` lines as failures.
+- Commit only when asked. Co-author trailer, when requested: `Co-Authored-By: Codex <noreply@openai.com>`.
+- The working tree may contain an untracked `Fuchs_Database/` SQL project — it is **not** part of app changes; never `git add -A` it into an unrelated commit. Stage explicit paths.
+
+## Coding Standards
+- C# only. Modern, performance-oriented .NET 10 (async/await, LINQ, DI).
+- Keep files <= 400 (max 600) lines; refactor larger files into focused classes.
+- PascalCase types/methods, camelCase locals/params.
+
+## Configuration
+- All settings in `Fuchs/appsettings.json` — **never** `Web.config` / `System.Configuration.ConfigurationManager`. App settings nested under `"Fuchs"`; connection strings under `"ConnectionStrings"`.
+- `FuchsOcmsIntranet.Initialize(configuration)` runs in `Program.cs` before DI registration.
+- `appsettings.Development.json` (git-ignored) overrides secrets locally.
+- `Fuchs:Email:OverrideRecipient` (`IOptions<FuchsEmailSettings>`, section `Fuchs:Email`) is a dev/test safety net: when non-empty, `ProcessWebComService.SendEmailAsync` discards the real recipient of every outbound email and redirects it to this single address instead, so a locally-enabled mailer can never reach a real tenant-owner or end-customer. Set only in `appsettings.Development.json` — must stay empty in Production.
+
+## Libraries
+- Do **not** upgrade Spire.PDF beyond 8.10.5. Prefer OCORE / OCORE_web / OCORE_web_pdf helpers over rewriting. Do not use OCMS/OCMS_sharp — OCORE only.
+
+## Services & Dependency Injection
+- Business logic lives in **DI-registered services** under `Fuchs/Services/` behind interfaces, injected into `IntranetController`. Do not reintroduce static God-classes or pass the controller into helpers.
+- Services: `IComService` (ProcessWeb Mailer API; honors the `Fuchs:Email:OverrideRecipient` dev safety net — see Configuration), `IPdfService`, `IInvoiceService`, `IReminderService`, `IReportService`, `IWidgetService`, `IBankingService`, `IMfrClientFactory`, `ISystemStatusService` (Admin module diagnostics: config snapshot + DB/Key Vault/blob/MFR connectivity probes + test-email; restricted to `fds_sys` > 4). Stateless ones are singletons; DB/request-scoped ones are scoped (see `Program.cs`).
+- `FdsInvoiceData` / `FdsReminderData` are **pure data holders**; load/persist/render belongs in services. No `Task.Run(...).Wait()` sync-over-async.
+- Data access is SQL-first via OCORE helpers + stored procedures (no EF Core).
+
+## MFR ERP integration
+- `MFR_RESTClient` is the REST/OData client for the **mfr (Mobile Field Report)** ERP. Its contract (base URLs, auth, OData conventions, pagination, error/retry, deep-create + document-upload) is in **`MFR_RESTClient/Docs/mfr_interface_description.md`** — read it before changing the client.
+- HTTP Basic auth; configurable timeout; idempotent GETs retry on transient errors (429/5xx, network/timeout) with backoff. Create clients via `IMfrClientFactory`. Active project is `MFR_RESTClient.csproj` (legacy `.vbproj` removed).
+
+## Database
+- Schema source of truth: **`Fuchs_Database`** SSDT project. SQL-first backend (stored procs, table types e.g. `fds__tt__bankingtransactions`, functions via OCORE — no EF Core).
+- Changing a proc signature or table type -> update the SSDT project **and** the calling C# together; verify every `[dbo].[…]` the backend calls exists in `Fuchs_Database`.
+
+## Bank statement parsing (MT940 + CAMT)
+- `MT940Parser` (external, SWIFT text) and **`CAMTParser`** (in-repo, ISO 20022 camt.052/053/054 XML) feed the same pipeline.
+- `BankingService.ParseToDatatable` auto-detects (XML -> CAMT, else MT940) -> `fds__tt__bankingtransactions`. `bam/up` + the frontend accept both formats. `CAMTParser` is namespace-agnostic. Keep both column mappings aligned with the banking schema.
+
+## Observability
+- OpenTelemetry. Instrumentation is centralised in `Fuchs/Observability/FuchsTelemetry.cs` (one `ActivitySource`, one `Meter`).
+- For meaningful operations: start an activity, record the matching counter/histogram, and log entry/result/timing/errors via injected `ILogger<T>` using **structured** placeholders (never interpolated strings).
+- Always collected; OTLP export opt-in via `Fuchs:Telemetry:OtlpEndpoint`. No exporters that hard-fail without a collector.
+
+## Testing
+- xUnit in `Fuchs.Tests`. Testing must be **extensive**, not superficial:
+  - For each service/handler change, cover **both** an intentionally succeeding and an intentionally failing path where feasible (stubs/mocks; `InternalsVisibleTo` is enabled).
+  - Cover edge cases and boundary conditions (empty/null/invalid input, disabled/feature-flag-off states, API/network errors) via `[Theory]`/`[InlineData]`/`[MemberData]` rather than a single happy-path `[Fact]`.
+  - When behavior depends on configuration (e.g. `appsettings.json` vs `appsettings.Development.json`), prefer loading the **real** files layered the same way ASP.NET Core does (`ConfigurationBuilder` + `AddJsonFile`) over hand-typed literals only, so drift in the actual files is caught (see `ProcessWebComServiceTests.SendEmailAsync_OverrideRecipientFromRealAppsettings_ClearsRecipientWheneverConfigured` for the pattern).
+  - Assert on the observable contract (e.g. the outgoing request payload) and on emitted telemetry (counters/histograms) when the code records them — not just the boolean return value.
+  - Name tests `MethodName_Scenario_ExpectedResult`.
+  - Cover pure logic for DB-bound paths that can't be unit-tested.
+
+## Secrets (Azure Key Vault)
+- Full naming rules live in `.github/copilot-instructions.md` (kept in sync). In short: names match `^[0-9a-zA-Z-]+$`, hierarchy via `--` (-> `:`), underscores -> `-`, app prefix `fuchs`; register new keys in `ManagedSecretKeys` in `appsettings.json`.
+
+## Decisions & Concepts
+- `Fuchs/Docs/Decisions/` holds immutable ADRs (architecture decision records); `Fuchs/Docs/Concepts/` holds living design write-ups kept in sync with the code. Each folder's `README.md` explains the format, naming, and required YAML frontmatter — **read it before creating or editing entries there.**
+- **Accepted decisions must be followed.** Before working in an area covered by a decision, read it and conform to it; don't silently deviate. Every file's YAML frontmatter has an `applyTo` glob — scan frontmatter across the folder first (cheap) and only read the full body of entries relevant to the files you're touching.
+- **Capture new decisions and concepts as they happen.** When a non-obvious architectural or cross-cutting choice gets settled (by the user or in the course of implementation), add a decision in `Docs/Decisions` in the same change, and create/update the matching concept doc in `Docs/Concepts` if the subsystem's design is otherwise non-obvious from the code.
+
+## Documentation map
+- `Fuchs/Docs/ARCHITECTURE.md` — solution architecture (keep current when structure changes).
+- `Fuchs/Docs/USER_GUIDE.md` — end-user process guide.
+- `Fuchs/Docs/Decisions/` — ADRs; see `Decisions & Concepts` above.
+- `Fuchs/Docs/Concepts/` — living subsystem design docs; see `Decisions & Concepts` above.
+- `MFR_RESTClient/Docs/mfr_interface_description.md` — mfr ERP REST/OData interface contract.
+- `.github/instructions/*.instructions.md` — domain-specific contributor guidance.

DataService_Legacy/App.config

@@ -1,131 +0,0 @@
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-    <add name="fuchs_fds_ConnectionString" connectionString="Data Source=MSSQL4.NBG4.DOMAINXYZ.DE,10439;Initial Catalog=site_fuchs;Persist Security Info=False;TrustServerCertificate=true;Encrypt=true;User ID=fuchs_fds;password='!Po@cGZ5bUn37khO';Connect Timeout=60;Load Balance Timeout=240;Max Pool Size=500;" providerName="System.Data.SqlClient" />
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-    <startup> 
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-    </startup>
-    <applicationSettings>
-        <fds.My.MySettings>
-            <setting name="ExecutionFrequency_Minutes" serializeAs="String">
-                <value>15</value>
-            </setting>
-            <setting name="DebugDetails" serializeAs="String">
-                <value>True</value>
-            </setting>
-            <setting name="MFR_UserName" serializeAs="String">
-                <value>system@sebastian-fuchs---bad-und-heizung-gmbh-und-co-kg.com</value>
-            </setting>
-            <setting name="MFR_Password" serializeAs="String">
-                <value>0oT4G3H2</value>
-            </setting>
-            <setting name="MFR_host" serializeAs="String">
-                <value>portal.mobilefieldreport.com</value>
-            </setting>
-        </fds.My.MySettings>
-    </applicationSettings>
-  <runtime>
-    <assemblyBinding xmlns="urn:schemas-microsoft-com:asm.v1">
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-    <MyType>Console</MyType>
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DataService_Legacy/My Project/AssemblyInfo.vb

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-Imports System
-Imports System.Reflection
-Imports System.Runtime.InteropServices
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-' General Information about an assembly is controlled through the following
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-' Review the values of the assembly attributes
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-'      Minor Version
-'      Build Number
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-        
-        '''<summary>
-        '''  Overrides the current thread's CurrentUICulture property for all
-        '''  resource lookups using this strongly typed resource class.
-        '''</summary>
-        <Global.System.ComponentModel.EditorBrowsableAttribute(Global.System.ComponentModel.EditorBrowsableState.Advanced)>  _
-        Friend Property Culture() As Global.System.Globalization.CultureInfo
-            Get
-                Return resourceCulture
-            End Get
-            Set
-                resourceCulture = value
-            End Set
-        End Property
-    End Module
-End Namespace

DataService_Legacy/My Project/Resources.resx

@@ -1,117 +0,0 @@
-<?xml version="1.0" encoding="utf-8"?>
-<root>
-  <!-- 
-    Microsoft ResX Schema 
-    
-    Version 2.0
-    
-    The primary goals of this format is to allow a simple XML format 
-    that is mostly human readable. The generation and parsing of the 
-    various data types are done through the TypeConverter classes 
-    associated with the data types.
-    
-    Example:
-    
-    ... ado.net/XML headers & schema ...
-    <resheader name="resmimetype">text/microsoft-resx</resheader>
-    <resheader name="version">2.0</resheader>
-    <resheader name="reader">System.Resources.ResXResourceReader, System.Windows.Forms, ...</resheader>
-    <resheader name="writer">System.Resources.ResXResourceWriter, System.Windows.Forms, ...</resheader>
-    <data name="Name1"><value>this is my long string</value><comment>this is a comment</comment></data>
-    <data name="Color1" type="System.Drawing.Color, System.Drawing">Blue</data>
-    <data name="Bitmap1" mimetype="application/x-microsoft.net.object.binary.base64">
-        <value>[base64 mime encoded serialized .NET Framework object]</value>
-    </data>
-    <data name="Icon1" type="System.Drawing.Icon, System.Drawing" mimetype="application/x-microsoft.net.object.bytearray.base64">
-        <value>[base64 mime encoded string representing a byte array form of the .NET Framework object]</value>
-        <comment>This is a comment</comment>
-    </data>
-                
-    There are any number of "resheader" rows that contain simple 
-    name/value pairs.
-    
-    Each data row contains a name, and value. The row also contains a 
-    type or mimetype. Type corresponds to a .NET class that support 
-    text/value conversion through the TypeConverter architecture. 
-    Classes that don't support this are serialized and stored with the 
-    mimetype set.
-    
-    The mimetype is used for serialized objects, and tells the 
-    ResXResourceReader how to depersist the object. This is currently not 
-    extensible. For a given mimetype the value must be set accordingly:
-    
-    Note - application/x-microsoft.net.object.binary.base64 is the format 
-    that the ResXResourceWriter will generate, however the reader can 
-    read any of the formats listed below.
-    
-    mimetype: application/x-microsoft.net.object.binary.base64
-    value   : The object must be serialized with 
-            : System.Serialization.Formatters.Binary.BinaryFormatter
-            : and then encoded with base64 encoding.
-    
-    mimetype: application/x-microsoft.net.object.soap.base64
-    value   : The object must be serialized with 
-            : System.Runtime.Serialization.Formatters.Soap.SoapFormatter
-            : and then encoded with base64 encoding.
-
-    mimetype: application/x-microsoft.net.object.bytearray.base64
-    value   : The object must be serialized into a byte array 
-            : using a System.ComponentModel.TypeConverter
-            : and then encoded with base64 encoding.
-    -->
-  <xsd:schema id="root" xmlns="" xmlns:xsd="http://www.w3.org/2001/XMLSchema" xmlns:msdata="urn:schemas-microsoft-com:xml-msdata">
-    <xsd:element name="root" msdata:IsDataSet="true">
-      <xsd:complexType>
-        <xsd:choice maxOccurs="unbounded">
-          <xsd:element name="metadata">
-            <xsd:complexType>
-              <xsd:sequence>
-                <xsd:element name="value" type="xsd:string" minOccurs="0" />
-              </xsd:sequence>
-              <xsd:attribute name="name" type="xsd:string" />
-              <xsd:attribute name="type" type="xsd:string" />
-              <xsd:attribute name="mimetype" type="xsd:string" />
-            </xsd:complexType>
-          </xsd:element>
-          <xsd:element name="assembly">
-            <xsd:complexType>
-              <xsd:attribute name="alias" type="xsd:string" />
-              <xsd:attribute name="name" type="xsd:string" />
-            </xsd:complexType>
-          </xsd:element>
-          <xsd:element name="data">
-            <xsd:complexType>
-              <xsd:sequence>
-                <xsd:element name="value" type="xsd:string" minOccurs="0" msdata:Ordinal="1" />
-                <xsd:element name="comment" type="xsd:string" minOccurs="0" msdata:Ordinal="2" />
-              </xsd:sequence>
-              <xsd:attribute name="name" type="xsd:string" msdata:Ordinal="1" />
-              <xsd:attribute name="type" type="xsd:string" msdata:Ordinal="3" />
-              <xsd:attribute name="mimetype" type="xsd:string" msdata:Ordinal="4" />
-            </xsd:complexType>
-          </xsd:element>
-          <xsd:element name="resheader">
-            <xsd:complexType>
-              <xsd:sequence>
-                <xsd:element name="value" type="xsd:string" minOccurs="0" msdata:Ordinal="1" />
-              </xsd:sequence>
-              <xsd:attribute name="name" type="xsd:string" use="required" />
-            </xsd:complexType>
-          </xsd:element>
-        </xsd:choice>
-      </xsd:complexType>
-    </xsd:element>
-  </xsd:schema>
-  <resheader name="resmimetype">
-    <value>text/microsoft-resx</value>
-  </resheader>
-  <resheader name="version">
-    <value>2.0</value>
-  </resheader>
-  <resheader name="reader">
-    <value>System.Resources.ResXResourceReader, System.Windows.Forms, Version=2.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089</value>
-  </resheader>
-  <resheader name="writer">
-    <value>System.Resources.ResXResourceWriter, System.Windows.Forms, Version=2.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089</value>
-  </resheader>
-</root>

DataService_Legacy/My Project/Settings.Designer.vb

@@ -1,118 +0,0 @@
-'------------------------------------------------------------------------------
-' <auto-generated>
-'     This code was generated by a tool.
-'     Runtime Version:4.0.30319.42000
-'
-'     Changes to this file may cause incorrect behavior and will be lost if
-'     the code is regenerated.
-' </auto-generated>
-'------------------------------------------------------------------------------
-
-Option Strict On
-Option Explicit On
-
-
-Namespace My
-    
-    <Global.System.Runtime.CompilerServices.CompilerGeneratedAttribute(),  _
-     Global.System.CodeDom.Compiler.GeneratedCodeAttribute("Microsoft.VisualStudio.Editors.SettingsDesigner.SettingsSingleFileGenerator", "16.8.1.0"),  _
-     Global.System.ComponentModel.EditorBrowsableAttribute(Global.System.ComponentModel.EditorBrowsableState.Advanced)>  _
-    Partial Friend NotInheritable Class MySettings
-        Inherits Global.System.Configuration.ApplicationSettingsBase
-        
-        Private Shared defaultInstance As MySettings = CType(Global.System.Configuration.ApplicationSettingsBase.Synchronized(New MySettings()),MySettings)
-        
-#Region "My.Settings Auto-Save Functionality"
-#If _MyType = "WindowsForms" Then
-    Private Shared addedHandler As Boolean
-
-    Private Shared addedHandlerLockObject As New Object
-
-    <Global.System.Diagnostics.DebuggerNonUserCodeAttribute(), Global.System.ComponentModel.EditorBrowsableAttribute(Global.System.ComponentModel.EditorBrowsableState.Advanced)> _
-    Private Shared Sub AutoSaveSettings(sender As Global.System.Object, e As Global.System.EventArgs)
-        If My.Application.SaveMySettingsOnExit Then
-            My.Settings.Save()
-        End If
-    End Sub
-#End If
-#End Region
-        
-        Public Shared ReadOnly Property [Default]() As MySettings
-            Get
-                
-#If _MyType = "WindowsForms" Then
-               If Not addedHandler Then
-                    SyncLock addedHandlerLockObject
-                        If Not addedHandler Then
-                            AddHandler My.Application.Shutdown, AddressOf AutoSaveSettings
-                            addedHandler = True
-                        End If
-                    End SyncLock
-                End If
-#End If
-                Return defaultInstance
-            End Get
-        End Property
-        
-        <Global.System.Configuration.ApplicationScopedSettingAttribute(),  _
-         Global.System.Diagnostics.DebuggerNonUserCodeAttribute(),  _
-         Global.System.Configuration.DefaultSettingValueAttribute("15")>  _
-        Public ReadOnly Property ExecutionFrequency_Minutes() As String
-            Get
-                Return CType(Me("ExecutionFrequency_Minutes"),String)
-            End Get
-        End Property
-        
-        <Global.System.Configuration.ApplicationScopedSettingAttribute(),  _
-         Global.System.Diagnostics.DebuggerNonUserCodeAttribute(),  _
-         Global.System.Configuration.DefaultSettingValueAttribute("True")>  _
-        Public ReadOnly Property DebugDetails() As Boolean
-            Get
-                Return CType(Me("DebugDetails"),Boolean)
-            End Get
-        End Property
-        
-        <Global.System.Configuration.ApplicationScopedSettingAttribute(),  _
-         Global.System.Diagnostics.DebuggerNonUserCodeAttribute(),  _
-         Global.System.Configuration.DefaultSettingValueAttribute("system@sebastian-fuchs---bad-und-heizung-gmbh-und-co-kg.com")>  _
-        Public ReadOnly Property MFR_UserName() As String
-            Get
-                Return CType(Me("MFR_UserName"),String)
-            End Get
-        End Property
-        
-        <Global.System.Configuration.ApplicationScopedSettingAttribute(),  _
-         Global.System.Diagnostics.DebuggerNonUserCodeAttribute(),  _
-         Global.System.Configuration.DefaultSettingValueAttribute("0oT4G3H2")>  _
-        Public ReadOnly Property MFR_Password() As String
-            Get
-                Return CType(Me("MFR_Password"),String)
-            End Get
-        End Property
-        
-        <Global.System.Configuration.ApplicationScopedSettingAttribute(),  _
-         Global.System.Diagnostics.DebuggerNonUserCodeAttribute(),  _
-         Global.System.Configuration.DefaultSettingValueAttribute("portal.mobilefieldreport.com")>  _
-        Public ReadOnly Property MFR_host() As String
-            Get
-                Return CType(Me("MFR_host"),String)
-            End Get
-        End Property
-    End Class
-End Namespace
-
-Namespace My
-    
-    <Global.Microsoft.VisualBasic.HideModuleNameAttribute(),  _
-     Global.System.Diagnostics.DebuggerNonUserCodeAttribute(),  _
-     Global.System.Runtime.CompilerServices.CompilerGeneratedAttribute()>  _
-    Friend Module MySettingsProperty
-        
-        <Global.System.ComponentModel.Design.HelpKeywordAttribute("My.Settings")>  _
-        Friend ReadOnly Property Settings() As Global.fds.My.MySettings
-            Get
-                Return Global.fds.My.MySettings.Default
-            End Get
-        End Property
-    End Module
-End Namespace

DataService_Legacy/My Project/Settings.settings

@@ -1,21 +0,0 @@
-<?xml version='1.0' encoding='utf-8'?>
-<SettingsFile xmlns="http://schemas.microsoft.com/VisualStudio/2004/01/settings" CurrentProfile="(Default)" GeneratedClassNamespace="My" GeneratedClassName="MySettings" UseMySettingsClassName="true">
-  <Profiles />
-  <Settings>
-    <Setting Name="ExecutionFrequency_Minutes" Type="System.String" Scope="Application">
-      <Value Profile="(Default)">15</Value>
-    </Setting>
-    <Setting Name="DebugDetails" Type="System.Boolean" Scope="Application">
-      <Value Profile="(Default)">True</Value>
-    </Setting>
-    <Setting Name="MFR_UserName" Type="System.String" Scope="Application">
-      <Value Profile="(Default)">system@sebastian-fuchs---bad-und-heizung-gmbh-und-co-kg.com</Value>
-    </Setting>
-    <Setting Name="MFR_Password" Type="System.String" Scope="Application">
-      <Value Profile="(Default)">0oT4G3H2</Value>
-    </Setting>
-    <Setting Name="MFR_host" Type="System.String" Scope="Application">
-      <Value Profile="(Default)">portal.mobilefieldreport.com</Value>
-    </Setting>
-  </Settings>
-</SettingsFile>

DataService_Legacy/fds_debug.vb

@@ -1,134 +0,0 @@
-Option Explicit On
-
-
-
-
-Partial Friend Module fds_debug
-
-    <Diagnostics.DebuggerStepThrough>
-    Public Function LogFile(FileName As String) As IO.FileInfo
-        Return New IO.FileInfo(AppBaseDirectory().FullName & FileName)
-    End Function
-
-
-    <Diagnostics.DebuggerStepThrough>
-    Public Function AppBaseDirectory() As IO.DirectoryInfo
-        Dim path As String = AppDomain.CurrentDomain.BaseDirectory + "tmp\"
-        Dim di As New IO.DirectoryInfo(path)
-        If di.Exists = True Then
-            Return di
-        ElseIf My.Computer.FileSystem.DirectoryExists(AppDomain.CurrentDomain.BaseDirectory) = True Then
-            di.Create()
-            Return di
-        Else : Return Nothing
-        End If
-    End Function
-
-    <Diagnostics.DebuggerStepThrough>
-    Public Sub DebugLog_async(CodeReference As String, SQLConnectionString As String, Optional exc As Exception = Nothing, Optional data As String = "", Optional context As Object = Nothing)
-        If CodeReference = "" OrElse SQLConnectionString = "" Then Exit Sub
-        Try
-            Threading.Tasks.Task.Run(Sub() Call DebugLog_sync(CodeReference:=CodeReference, SQLConnectionString:=SQLConnectionString, exc:=exc, data:=data, context:=context))
-        Catch ex As Exception
-            Call DebugLog_sync(CodeReference:="fds_debug DebugLog_async", SQLConnectionString:=SQLConnectionString, exc:=ex, data:="", context:=Nothing)
-        End Try
-    End Sub
-
-    <Diagnostics.DebuggerStepThrough>
-    Public Sub DebugLog_sync(CodeReference As String, SQLConnectionString As String, Optional exc As Exception = Nothing, Optional data As String = "", Optional context As Object = Nothing)
-        If CodeReference = "" OrElse SQLConnectionString = "" Then Exit Sub
-        Using con As New SqlClient.SqlConnection(SQLConnectionString)
-            Call DebugLog(CodeReference:=CodeReference, SQLConnection:=con, exc:=exc, data:=data, context:=context)
-        End Using
-    End Sub
-
-
-    <Diagnostics.DebuggerStepThrough>
-    Public Sub DebugLog(CodeReference As String, SQLConnection As SqlClient.SqlConnection, Optional exc As Exception = Nothing, Optional data As String = "", Optional context As Object = Nothing)
-        If CodeReference = "" OrElse IsNothing(SQLConnection) = True Then Exit Sub
-        Dim note As String = Now.ToString("yyyy.MM.dd HH:mm:ss") & " - " & CodeReference
-        Try
-            Try
-                If IsNothing(SQLConnection) = False Then
-                    Dim pl As New List(Of SqlClient.SqlParameter) From {
-                    New SqlClient.SqlParameter("@CodeReference", CodeReference),
-                    New SqlClient.SqlParameter("@ExceptionMessage", If(IsNothing(exc), DBNull.Value, exc.Message)),
-                    New SqlClient.SqlParameter("@StackTrace", If(IsNothing(exc), DBNull.Value, exc.StackTrace.ToString)),
-                    New SqlClient.SqlParameter("@data", If(data, DBNull.Value))
-                }
-                    Try
-                        Dim w As Integer = 0
-                        If SQLConnection.State = ConnectionState.Broken Then SQLConnection.Close()
-                        If SQLConnection.State = ConnectionState.Connecting Then
-                            w = 0
-                            While SQLConnection.State = ConnectionState.Connecting And w < 10
-                                System.Threading.Thread.Sleep(100)
-                                w += 1
-                            End While
-                        ElseIf Not SQLConnection.State = ConnectionState.Open Then
-                            SQLConnection.Open()
-                        End If
-                        w = 0
-                        While Not SQLConnection.State = ConnectionState.Open And w < 10
-                            System.Threading.Thread.Sleep(100)
-                            w += 1
-                        End While
-                        Dim cmd As New SqlClient.SqlCommand("EXECUTE [dbo].[fds__admin_logdebug] @CodeReference,@ExceptionMessage,@StackTrace,@Data;", SQLConnection)
-                        cmd.Parameters.AddRange(pl.ToArray)
-                        Call cmd.ExecuteNonQuery()
-                        'SQLConnection.Close()
-                        cmd.Parameters.Clear()
-
-                    Catch sqlex As Exception
-                    End Try
-
-                End If
-            Catch dbex As Exception
-
-            End Try
-
-            If IsNothing(exc) = False Then
-                note &= (vbCrLf & "Exception:" & exc.Message & vbCrLf & "Stack:" & exc.StackTrace.ToString).Replace(vbLf, vbLf & "     ")
-            End If
-            If data <> "" Then
-                note &= (vbCrLf & "Data:" & data).Replace(vbLf, vbLf & "     ")
-            End If
-            note &= vbCrLf
-
-            Dim DebugLogfile As IO.FileInfo = LogFile("DebugLog.txt")
-            If DebugLogfile.Directory.Exists = True Then
-                IO.File.AppendAllText(DebugLogfile.FullName, note)
-            End If
-        Catch logex As Exception
-
-        Finally
-
-            Console.Write(note)
-            Debug.Print(note)
-        End Try
-    End Sub
-
-    Public Sub DebugToFile(note As String, Optional filename As String = "DebugLog.txt")
-        Try
-            Dim DebugLogfile As IO.FileInfo = LogFile(filename)
-            If DebugLogfile.Directory.Exists = True Then
-                IO.File.AppendAllText(DebugLogfile.FullName, Now.ToString & ": " & note & vbCrLf)
-            End If
-        Catch ex As Exception
-        End Try
-    End Sub
-    Public Sub DebugToFile(CodeReference As String, exc As Exception, data As String, Optional filename As String = "DebugLog.txt")
-        Dim note As String = CodeReference
-        If IsNothing(exc) = False Then
-            note &= (vbCrLf & "Exception:" & exc.Message & vbCrLf & "Stack:" & exc.StackTrace.ToString).Replace(vbLf, vbLf & "     ")
-        End If
-        If data <> "" Then
-            note &= (vbCrLf & "Data:" & data).Replace(vbLf, vbLf & "     ")
-        End If
-
-        Call DebugToFile(note, filename:=filename)
-    End Sub
-
-
-
-End Module

DataService_Legacy/fds_main.vb

@@ -1,146 +0,0 @@
-
-Imports Topshelf
-Imports json = Newtonsoft.Json.JsonConvert
-
-
-
-Public Class fds_service
-    Implements Topshelf.ServiceControl
-
-    Dim WithEvents _timer As System.Timers.Timer
-
-    Public Sub New()
-        Me._timer = New System.Timers.Timer(My.Settings.ExecutionFrequency_Minutes * 60 * 1000) With {.AutoReset = True}
-
-    End Sub
-
-
-    Public Function Start(hostControl As HostControl) As Boolean Implements ServiceControl.Start
-        Me._timer.Start()
-        Return True
-    End Function
-    Public Function StartImmediately(hostControl As HostControl) As Boolean
-        Me._timer.Start()
-        System.Threading.Tasks.Task.Run(Sub()
-                                            If My.Settings.DebugDetails = True Then Call DebugToFile("fds__data_service - timer started with interval " & _timer.Interval.ToString, filename:="DebugDetail.txt")
-                                            Call update_mfr()  'start right away and do not wait until first intervall period is over
-                                        End Sub)
-        'do not wait and immediately return
-        Return True
-    End Function
-
-    Public Function [Stop](hostControl As HostControl) As Boolean Implements ServiceControl.Stop
-        Me._timer.Stop()
-        If My.Settings.DebugDetails = True Then System.Threading.Tasks.Task.Run(Sub() Call DebugToFile("fds__data_service - timer stopped", filename:="DebugDetail.txt"))
-
-        Return True
-    End Function
-
-
-    Public Sub timerElapsed() Handles _timer.Elapsed
-        Call update_mfr()
-    End Sub
-
-    Friend Shared Sub update_mfr()
-        If My.Settings.DebugDetails = True Then Call DebugToFile("fds__data_service update_mfr UpdateIfNecessary - timer elapsed", filename:="DebugDetail.txt")
-        'call update to data if necessary
-        Try
-            Dim t As Threading.Tasks.Task = Threading.Tasks.Task.Run(Async Function()
-                                                                         'Await UpdateIfNecessary_Single_async(et:=MFR_RESTClient.generic._generic.EntityTypes.Report, DebugDetails:=My.Settings.DebugDetails)
-                                                                         Await UpdateIfNecessary_async(DebugDetails:=My.Settings.DebugDetails)
-                                                                         Await UpdateRequested_async(DebugDetails:=My.Settings.DebugDetails)
-                                                                         Await GetInvoiceFiles_async(DebugDetails:=My.Settings.DebugDetails)
-                                                                         'Await getDatevZip()
-                                                                     End Function)
-            t.Wait()
-        Catch ex As Exception
-            Call DebugLog("fds__data_service update_mfr UpdateIfNecessary", SQLConnection:=Nothing, exc:=ex)
-            If My.Settings.DebugDetails = True Then Call DebugToFile("fds__data_service update_mfr UpdateIfNecessary", exc:=ex, data:="", filename:="DebugDetail.txt")
-        End Try
-    End Sub
-
-End Class
-
-
-
-Public Module fds_main
-
-    Sub Main()
-        Dim clArgs() As String = Environment.GetCommandLineArgs()
-
-        If (New String() {"digital-pc", "digital-dpc"}).Contains(Environment.MachineName.ToLower) = False Then
-
-            HostFactory.Run(Sub(x)
-                                x.Service(Of fds_service)(AddressOf ServiceConfiguratorCallback)
-                                x.EnablePauseAndContinue()
-                                x.StartAutomatically()
-                                x.RunAsLocalSystem()
-                                x.SetDescription("MFR Data Sync")
-                                x.SetDisplayName("MFR Data Sync")
-                                x.SetServiceName("MFR Data Sync")
-                            End Sub)
-        Else
-            Call fds_service.update_mfr()
-            'Call DEv()
-        End If
-    End Sub
-
-    Private Sub ServiceConfiguratorCallback(s As ServiceConfigurators.ServiceConfigurator(Of fds_service))
-        s.ConstructUsing(Function(name) New fds_service())
-        s.WhenStarted(Function(tc, Host)
-                          Return tc.Start(Host)
-                      End Function)
-        s.WhenStopped(Function(tc, Host)
-                          Return tc.Stop(Host)
-                      End Function)
-        s.BeforeStoppingService(Sub(HostStopContext)
-                                    If My.Settings.DebugDetails = True Then System.Threading.Tasks.Task.Run(Sub() Call DebugToFile("fds__data_service - beforestop", filename:="DebugDetail.txt"))
-                                End Sub)
-        s.WhenPaused(Function(tc, Host)
-                         Return tc.Stop(Host)
-                     End Function)
-        s.WhenContinued(Function(tc, Host)
-                            Return tc.StartImmediately(Host)
-                        End Function)
-    End Sub
-
-
-
-    Public Sub DEv()
-        Using MFR As New fds_MFR_Client()
-            'Diagnostics.Debug.Print(MFR.ReadAnything(address:="https://portal.mobilefieldreport.com/odata/$metadata"))
-            'Diagnostics.Debug.Print(MFR.ReadAnything(address:="https://portal.mobilefieldreport.com/odata/Companies?$top=5&$expand=Contacts,Tags,ServiceObjects,MainContact"))
-            'Diagnostics.Debug.Print(MFR.ReadAnything(address:="https://portal.mobilefieldreport.com/odata/ServiceObjects?$expand=WarehouseManager,CustomValueSteps,Company,Product,Tags,ChildServiceObject,Contacts,Items"))
-            'Diagnostics.Debug.Print(MFR.ReadAnything(address:="https://portal.mobilefieldreport.com/odata/Contacts/$count"))
-            'Diagnostics.Debug.Print(MFR.getEntities())
-            Dim fle As Byte()
-            Try
-                fle = MFR.GetFile("https://portal.mobilefieldreport.com/mfr/Report/19584712737/Content/")
-                System.IO.File.WriteAllBytes("C:\Users\sailo\Desktop\Test.pdf", fle)
-            Catch ex As Exception
-
-            End Try
-        End Using
-
-    End Sub
-
-
-
-
-
-End Module
-
-
-
-Partial Friend Module fds_debug
-
-
-    Public Sub DebugLog(CodeReference As String, Optional exc As Exception = Nothing, Optional data As String = "", Optional context As Object = Nothing, Optional execute_async As Boolean = True)
-        If execute_async = True Then
-            Call DebugLog_async(CodeReference:=CodeReference, SQLConnectionString:=FDSConnectionString(), exc:=exc, data:=data, context:=context)
-        Else
-            Call DebugLog_sync(CodeReference:=CodeReference, SQLConnectionString:=FDSConnectionString(), exc:=exc, data:=data, context:=context)
-        End If
-    End Sub
-
-End Module

DataService_Legacy/fds_shared.vb

@@ -1,226 +0,0 @@
-
-
-Friend Module fds_shared
-
-    Friend Function SQLConnectionString() As String
-        Return Configuration.ConfigurationManager.ConnectionStrings("fuchs_ConnectionString").ConnectionString
-    End Function
-    Friend Function FDSConnectionString() As String
-        Return Configuration.ConfigurationManager.ConnectionStrings("fuchs_fds_ConnectionString").ConnectionString
-    End Function
-    Friend Function SqlCon() As SqlClient.SqlConnection
-        Return New SqlClient.SqlConnection(Configuration.ConfigurationManager.ConnectionStrings("fuchs_ConnectionString").ConnectionString)
-    End Function
-
-
-
-    Public Function RandomString(rs_length As Byte) As String
-        Dim r As New Random()
-        Dim s As String = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789"
-        Dim sb As New Text.StringBuilder
-        For i As Byte = 1 To rs_length
-            Dim idx As Integer = r.Next(0, s.Length)
-            sb.Append(s.Substring(idx, 1))
-        Next
-        Return sb.ToString()
-    End Function
-
-
-    '''' <summary>
-    '''' Returns a delimited <see cref="String" /> containing the field values from a <see cref="DataRow" />.
-    '''' </summary>
-    '''' <param name="source">
-    '''' The input <see cref="DataRow" />.
-    '''' </param>
-    '''' <param name="delimiter">
-    '''' The delimiter placed between field values. the default value is a comma.
-    '''' </param>
-    '''' <returns>
-    '''' A <see cref="String"/> containing the field values from the row separated by the specified delimiter.
-    '''' </returns>
-    '<Runtime.CompilerServices.Extension>
-    'Public Function ToCsv(source As DataRow,
-    '                      Optional delimiter As String = ",") As String
-    '    Return String.Join(delimiter, source.ItemArray)
-    'End Function
-
-    ''' <summary>
-    ''' Returns a delimited <see cref="String" /> containing the field values from a <see cref="DataRow" />.
-    ''' </summary>
-    ''' <param name="source">
-    ''' The input <see cref="DataRow" />.
-    ''' </param>
-    ''' <param name="quoteStrings">
-    ''' <b>True</b> to wrap <see cref="String"/> values in double-quotes; otherwise, <b>False</b>.
-    ''' If double-quotes are added, double-quotes within text are escaped with another double-quote.
-    ''' </param>
-    ''' <param name="delimiter">
-    ''' The delimiter placed between field values. the default value is a comma.
-    ''' </param>
-    ''' <returns>
-    ''' A <see cref="String"/> containing the field values from the row separated by the specified delimiter.
-    ''' </returns>
-    <Runtime.CompilerServices.Extension>
-    Public Function ToCsv(source As DataRow,
-                          quoteStrings As Boolean,
-                          cultureinfo As Globalization.CultureInfo,
-                          Optional delimiter As String = ",") As String
-        Dim fieldValues = source.ItemArray
-
-
-        Dim rx As New Text.RegularExpressions.Regex("(\"")")
-        'Wrap any String values in double-quotes and also escape any double-quotes in the String with another double-quote.
-        'replace array by converted array
-        fieldValues = fieldValues.Select(Function(o)
-                                             If IsNothing(o) OrElse IsDBNull(o) Then
-                                                 Return ""
-                                             ElseIf o.GetType = GetType(String) Then
-                                                 If quoteStrings = True Then
-                                                     Return Microsoft.VisualBasic.ChrW(34) & rx.Replace(o.ToString, Microsoft.VisualBasic.ChrW(34) & Microsoft.VisualBasic.ChrW(34)) & Microsoft.VisualBasic.ChrW(34)
-                                                 Else
-                                                     Return o.ToString
-                                                 End If
-                                             Else
-                                                 Select Case o.GetType
-                                                     Case GetType(Decimal)
-                                                         Return DirectCast(o, Decimal).ToString(cultureinfo)
-                                                     Case GetType(Single)
-                                                         Return DirectCast(o, Single).ToString(cultureinfo)
-                                                     Case GetType(Double)
-                                                         Return DirectCast(o, Double).ToString(cultureinfo)
-                                                     Case GetType(Boolean)
-                                                         Return DirectCast(o, Boolean).ToString(cultureinfo)
-                                                     Case GetType(System.DateTime)
-                                                         Return DirectCast(o, DateTime).ToUniversalTime.ToString("U")
-                                                     Case Else
-                                                         Return o.ToString()
-                                                 End Select
-                                             End If
-                                         End Function).ToArray()
-
-
-        Return String.Join(delimiter, fieldValues)
-    End Function
-
-
-
-    ''' <summary>
-    ''' Returns a delimited <see cref="String" /> containing the field values from the rows a <see cref="DataTable" />.
-    ''' </summary>
-    ''' <param name="source">The input <see cref="DataTable" />.</param>
-    ''' <param name="includeHeaders"><b>True</b> to include a row of column headers; otherwise, <b>False</b></param>
-    ''' <param name="quoteStrings"><b>True</b> to wrap <see cref="String"/> values in double-quotes; otherwise, <b>False</b>.
-    ''' If double-quotes are added, double-quotes within text are escaped with another double-quote.</param>
-    ''' <param name="rowDelimiter">The delimiter placed between rows. the default value is a line break comprising a carriage return and a line feed.</param>
-    ''' <param name="fieldDelimiter">The delimiter placed between field values. the default value is a comma.</param>
-    ''' <param name="cultureinfo">The culture that is used to convert float-point numbers like <see cref="Decimal" /> or <see cref="Double"/> to string. <br/>This falls back to InvariantCulture, if not provided.</param>
-    ''' <param name="quoteHeader"><b>True</b> to wrap <see cref="String"/> column header names in double-quotes; otherwise, <b>False</b>.<br />
-    ''' If no value is provided, the settings falls back to <b>quoteStrings</b> parameter.</param>
-    ''' <returns>A <see cref="String"/> containing the field values from the rows of the table separated by the specified delimiters.</returns>
-    <Runtime.CompilerServices.Extension>
-    Public Function ToCsv(source As DataTable,
-                          includeHeaders As Boolean,
-                          quoteStrings As Boolean,
-                          Optional rowDelimiter As String = ControlChars.CrLf,
-                          Optional fieldDelimiter As String = ",",
-                          Optional cultureinfo As Globalization.CultureInfo = Nothing,
-                          Optional quoteHeader As Boolean? = Nothing) As String
-        If quoteHeader.HasValue = False Then quoteHeader = quoteStrings
-        cultureinfo = If(cultureinfo, Globalization.CultureInfo.InvariantCulture)  'fallback if not provided
-        Dim rows = source.Rows.
-                          Cast(Of DataRow)().
-                          Select(Function(row) row.ToCsv(quoteStrings:=quoteStrings, cultureinfo:=cultureinfo, delimiter:=fieldDelimiter))
-
-        If includeHeaders = True Then
-            Dim rx As New Text.RegularExpressions.Regex("(\"")")
-            Dim headers = String.Join(fieldDelimiter,
-                                      source.Columns.
-                                             Cast(Of DataColumn)().
-                                             Select(Function(column) If(quoteHeader.Value,
-                                                                        Microsoft.VisualBasic.ChrW(34) & rx.Replace(column.ColumnName.ToString, Microsoft.VisualBasic.ChrW(34) & Microsoft.VisualBasic.ChrW(34)) & Microsoft.VisualBasic.ChrW(34),
-                                                                        column.ColumnName)))
-
-            rows = {headers}.Concat(rows)
-        End If
-
-        Return String.Join(rowDelimiter, rows)
-    End Function
-
-    ''' <summary>
-    ''' Returns a text-file containing the string, created by streamwriter.
-    ''' </summary>
-    ''' <param name="input">The input <see cref="String"/>.</param>
-    ''' <param name="encoding">The encoding used with streamwriter for the textfile. This falls back to <see cref="System.Text.Encoding.utf8"/>, if not provided.</param>
-    ''' <returns>A file as byte-array.</returns>
-    <Runtime.CompilerServices.Extension>
-    Public Function ToByteArray(input As String, Optional encoding As System.Text.Encoding = Nothing) As Byte()
-        Dim content As Byte() = Nothing
-        Using ms As New IO.MemoryStream
-            Using sw As New IO.StreamWriter(ms, encoding:=If(encoding, System.Text.Encoding.UTF8))
-                sw.Write(input)
-                sw.Flush()
-                ms.Position = 0
-                content = ms.ToArray()
-            End Using
-        End Using
-        Return content
-    End Function
-
-
-    Public Function WriteStreamToDisk(ByVal StreamToWrite As IO.Stream, ByVal FilePath As String) As Boolean
-        'Dim tmpFilePath As String = Left(FilePath, Len(FilePath) - 4) & ".tmp"
-        Dim cnt = 0
-restart:
-        Try
-            If My.Computer.FileSystem.FileExists(FilePath) Then My.Computer.FileSystem.DeleteFile(FilePath)
-            Using FleStream As System.IO.FileStream = New System.IO.FileStream(FilePath, System.IO.FileMode.Create, System.IO.FileAccess.Write, System.IO.FileShare.Delete)
-                ReadWriteStream(StreamToWrite, FleStream, True)
-            End Using
-        Catch ex As Exception
-            System.Diagnostics.Debug.WriteLine($"{"WriteStreamToDisk - " & ex.Message}")
-            cnt += 1
-            If cnt = 6 Then
-                Return False
-                Exit Function
-            Else
-                Threading.Thread.Sleep(500)
-                GoTo restart
-            End If
-        End Try
-        Return True
-    End Function
-
-    Public Function ReadWriteStream(ByVal readStream As IO.Stream, ByVal writeStream As IO.Stream, ByVal closeWriteStream As Boolean) As Boolean
-        Try
-            Dim Length As Integer = 256
-            Dim buffer(Length - 1) As Byte
-            readStream.Seek(0, System.IO.SeekOrigin.Begin)
-            Dim bytesRead As Integer = readStream.Read(buffer, 0, Length)
-            'write the required bytes
-            While (bytesRead > 0)
-                writeStream.Write(buffer, 0, bytesRead)
-                bytesRead = readStream.Read(buffer, 0, Length)
-            End While
-            readStream.Close()
-            If closeWriteStream = True Then writeStream.Close()
-            Return True
-        Catch ex As Exception
-            System.Diagnostics.Debug.WriteLine($"{"ReadWriteStream - " & ex.Message}")
-            Call OCMS.debug_log("files_folders ReadWriteStream", ex)
-            Return False
-        End Try
-    End Function
-
-    <System.Diagnostics.DebuggerStepThrough()>
-    <Runtime.CompilerServices.Extension()>
-    Public Function NameBase(ByVal FI As System.IO.FileInfo) As String
-        Return FI.Name.Substring(startIndex:=0, length:=FI.Name.Length - FI.Extension.Length)
-    End Function
-
-
-    <System.Diagnostics.DebuggerStepThrough()>
-    <Runtime.CompilerServices.Extension()>
-    Public Function MimeType(ByVal FI As System.IO.FileInfo) As String
-        Return System.Web.MimeMapping.GetMimeMapping(FI.Name)
-    End Function
-End Module

DataService_Legacy/fds_zip.vb

@@ -1,500 +0,0 @@
-Imports SevenZip  'Squid-Box.SevenZipSharp
-Imports System.IO
-
-Namespace Global.fds
-    Public Class Archive
-        Implements IDisposable
-
-        'Private Declare Function WaitForSingleObject Lib "kernel32" (ByVal hHandle As Long, ByVal dwMilliseconds As Long) As Long
-        'Private Declare Sub Sleep Lib "kernel32" (ByVal dwMilliseconds As Long)
-
-        'Public Enum Timeunit As Long
-        '    Milliseconds = 0
-        '    Seconds = 1000
-        '    Minutes = 60000
-        'End Enum
-        'Public Sub Wait(ByVal No As Integer, ByVal unit As Timeunit)
-        '    Dim tme As Long = CLng(No * unit)
-        '    Sleep(tme)
-        'End Sub
-
-        Public Event Saving()
-        Public Event FileSaved()
-        Public Event FileStreamCreated()
-
-        Private _ArchiveFile As FileInfo
-        Private _ArchivePassword As String
-        Private _ArchiveFormat As OutArchiveFormat
-        Public TempPath As String = System.AppDomain.CurrentDomain.BaseDirectory
-        Public Property ArchiveFileStream As IO.Stream
-
-        Private ZipOut As SevenZipExtractor
-        Private ZipIn As SevenZipCompressor
-        Public ZipAppend As Boolean = True
-
-        Public ExitOK As Boolean = False
-        Public ZipInOK As Boolean = False
-
-        Public Sub New(ByVal ArchiveFile As FileInfo, Optional ByVal ArchivePassword As String = "", Optional ByVal INIT As Boolean = True, Optional ByVal Type As OutArchiveFormat = OutArchiveFormat.SevenZip)
-            Me._ArchiveFormat = Type
-            Me._ArchiveFile = New FileInfo(ArchiveFile.FullName.Replace(ArchiveFile.Extension, If(Type = OutArchiveFormat.SevenZip, ".7z", ArchiveFile.Extension)))
-            Me._ArchivePassword = ArchivePassword
-            If INIT = True Then Call InitZipIn(Type)
-        End Sub
-
-        Private Sub InitZipIn(ByVal Type As OutArchiveFormat)
-            Dim assemblydirectory As IO.DirectoryInfo
-            If Zipping.SevenZipPath = "" Then
-                Try
-                    assemblydirectory = New IO.DirectoryInfo(New Uri(System.IO.Path.GetDirectoryName(System.Reflection.Assembly.GetExecutingAssembly().GetName().CodeBase)).LocalPath)
-                    Dim zip As IO.FileInfo = assemblydirectory.GetFiles("7z.dll", SearchOption.AllDirectories).FirstOrDefault
-                    Zipping.SevenZipPath = If(IsNothing(zip), "", zip.FullName)
-                Finally
-                    If Zipping.SevenZipPath = "" Then
-                        assemblydirectory = New IO.DirectoryInfo(System.AppDomain.CurrentDomain.BaseDirectory)
-                        Dim zip As IO.FileInfo = assemblydirectory.GetFiles("7z.dll", SearchOption.AllDirectories).FirstOrDefault
-                        Zipping.SevenZipPath = If(IsNothing(zip), "", zip.FullName)
-                    End If
-                End Try
-                If Zipping.SevenZipPath = "" Then
-                    OCMS.debug_log("DDA.intranet.Zipping Archive InitZipIn", error:="SevenZipPath not found")
-                End If
-            End If
-            SevenZipCompressor.SetLibraryPath(SevenZipPath)
-
-            Me.ZipIn = New SevenZipCompressor
-            With Me.ZipIn
-                If Type = OutArchiveFormat.SevenZip AndAlso Me._ArchiveFile.Extension.ToLower.Contains("7z") = True Then
-                    .ArchiveFormat = OutArchiveFormat.SevenZip
-                Else
-                    .ArchiveFormat = Type
-                End If
-
-                .CompressionLevel = SevenZip.CompressionLevel.Ultra
-                Select Case .ArchiveFormat
-                    Case OutArchiveFormat.SevenZip
-                        .CompressionMethod = SevenZip.CompressionMethod.Lzma2
-                    Case OutArchiveFormat.Zip, OutArchiveFormat.GZip
-                        .CompressionMethod = CompressionMethod.Deflate
-                    Case Else
-                        .CompressionMethod = CompressionMethod.Default
-                End Select
-
-                If ZipAppend = True Then
-                    .CompressionMode = SevenZip.CompressionMode.Append
-                Else
-                    .CompressionMode = SevenZip.CompressionMode.Create
-                End If
-                .DirectoryStructure = False
-            End With
-            Me.ZipInOK = True
-        End Sub
-
-        Public Sub Extract(ByVal DataArchiveFilePath As FileInfo, ByVal TgtDirectory As DirectoryInfo, Optional ByVal Type As OutArchiveFormat = Nothing)
-            If DataArchiveFilePath.Exists Then
-                If IsNothing(Type) = True AndAlso DataArchiveFilePath.Extension.ToLower.Contains("7z") = True Then
-                    Type = OutArchiveFormat.SevenZip
-                ElseIf IsNothing(Type) = True Then
-                    Type = OutArchiveFormat.Zip
-                End If
-
-                If Me.ZipInOK = False Then Call InitZipIn(Type)
-
-                If Me._ArchivePassword = "" Then
-                    Me.ZipOut = New SevenZipExtractor(DataArchiveFilePath.FullName)
-                Else
-                    Me.ZipOut = New SevenZipExtractor(DataArchiveFilePath.FullName, Me._ArchivePassword)
-                End If
-
-                Try
-                    If Me.ZipOut.ArchiveFileData(0).Encrypted = False And Not Me._ArchivePassword = "" Then
-                        Me._ArchivePassword = ""
-                    End If
-                Catch ex As Exception
-                    System.Diagnostics.Debug.WriteLine($"{"zip Extract - " & ex.Message}")
-                    OCMS.debug_log("DDA.intranet.Zipping Archive InitZipIn", ex:=ex, data:=New With {.DataArchiveFilePath = DataArchiveFilePath.FullName, .TgtDirectory = TgtDirectory.FullName})
-                    Exit Sub
-                End Try
-
-                If Not ZipOut Is Nothing Then
-                    Me.ZipOut.ExtractArchive(TgtDirectory.FullName)
-                    Me.ZipOut.Dispose()
-                End If
-            End If
-        End Sub
-
-        Public Function FileInfo_to_Filepaths_Converter() As Converter(Of FileInfo, String)
-            Return New Converter(Of FileInfo, String)(Function(filepath As FileInfo) filepath.FullName())
-        End Function
-        Public Function Filepaths_to_FileInfo_Converter() As Converter(Of String, FileInfo)
-            Return New Converter(Of String, FileInfo)(Function(filepath As String) New FileInfo(filepath))
-        End Function
-
-        Public Function Compress(ByVal FilePaths As List(Of String), Optional ByVal ArchiveFilePath As String = Nothing, Optional ByVal ArchivePass As String = Nothing, Optional ByVal Type As OutArchiveFormat = OutArchiveFormat.SevenZip) As Boolean
-            Return Compress(Files:=FilePaths.ConvertAll(Filepaths_to_FileInfo_Converter()), ArchiveFile:=If(IsNothing(ArchiveFilePath), Nothing, New FileInfo(ArchiveFilePath)), ArchivePass:=ArchivePass, Type:=Type)
-        End Function
-        Public Function Compress(ByVal Files As List(Of FileInfo), Optional ByVal ArchiveFile As FileInfo = Nothing, Optional ByVal ArchivePass As String = Nothing, Optional ByVal Type As OutArchiveFormat = OutArchiveFormat.SevenZip) As Boolean
-            If Files.Count = 0 Then Return True
-            If Me.ZipInOK = False Then Call InitZipIn(Type)
-
-            If IsNothing(ArchiveFile) = True Then ArchiveFile = Me._ArchiveFile
-            If If(IsNothing(ArchivePass), "", ArchivePass) = "" Then ArchivePass = Me._ArchivePassword
-
-            If ArchiveFile.Exists() AndAlso Me.ZipAppend = True Then
-                Me.ZipIn.CompressionMode = CompressionMode.Append
-            Else
-                If ArchiveFile.Exists = True Then ArchiveFile.Delete()
-                Me.ZipIn.CompressionMode = CompressionMode.Create
-            End If
-
-            Try
-                Dim FilesVerified As FileInfo() = Files.Where(Function(f As FileInfo) f.Exists).ToArray()
-                Dim FilePaths As String() = Array.ConvertAll(Of FileInfo, String)(FilesVerified, FileInfo_to_Filepaths_Converter())
-                If ArchivePass = "" Then
-                    Me.ZipIn.CompressFiles(ArchiveFile.FullName, FilePaths)
-                Else
-                    Me.ZipIn.EncryptHeaders = True
-                    Me.ZipIn.ZipEncryptionMethod = ZipEncryptionMethod.Aes256
-                    Me.ZipIn.CompressFilesEncrypted(ArchiveFile.FullName, ArchivePass, FilePaths)
-                End If
-                RaiseEvent FileSaved()
-
-                'Debug.Print("Saved: " & Now().ToString)
-                Me.ExitOK = True
-                'Disposing...
-                Me.ZipIn = Nothing
-                Me.ZipInOK = False
-            Catch ex As Exception
-                'Debug.Print("NOT Saved: " & Now().ToString)
-                Me.ExitOK = False
-            End Try
-            Return Me.ExitOK AndAlso ArchiveFile.Exists
-        End Function
-        Public Function Compress(ByVal FilePath As String) As Boolean
-            Dim FL As New List(Of String) From {
-                FilePath
-            }
-            Call Compress(FL)
-            Return True
-        End Function
-        Public Function CompressToStream(ByVal FilePath As String) As Boolean
-            Dim FL As New List(Of String) From {
-                FilePath
-            }
-            Call CompressToStream(FL)
-            Return True
-        End Function
-
-        Public Function CompressToStream(ByVal FilePaths As List(Of String)) As Boolean
-            Return CompressToStream(Files:=FilePaths.ConvertAll(Filepaths_to_FileInfo_Converter()))
-        End Function
-        Public Function CompressToStream(ByVal Files As List(Of FileInfo)) As Boolean
-            If Files.Count = 0 Then Return True
-            If Me.ZipInOK = False Then Call InitZipIn(Me._ArchiveFormat)
-
-            If IsNothing(_ArchiveFileStream) Then  'nur wenn der interne leer ist...
-                Me.ZipIn.CompressionMode = CompressionMode.Create
-                Me._ArchiveFileStream = New MemoryStream
-            Else
-                Me.ZipIn.CompressionMode = CompressionMode.Append
-            End If
-
-            Try
-                Dim FilesVerified As FileInfo() = Files.Where(Function(f As FileInfo) f.Exists).ToArray()
-                Dim FilePaths As String() = Array.ConvertAll(Of FileInfo, String)(FilesVerified, FileInfo_to_Filepaths_Converter())
-                If Me._ArchivePassword = "" Then
-                    Me.ZipIn.CompressFiles(Me._ArchiveFileStream, FilePaths)
-                Else
-                    Me.ZipIn.EncryptHeaders = True
-                    Me.ZipIn.ZipEncryptionMethod = ZipEncryptionMethod.Aes256
-                    Me.ZipIn.CompressFilesEncrypted(Me._ArchiveFileStream, Me._ArchivePassword, FilePaths)
-                End If
-                Me._ArchiveFileStream.Seek(0, SeekOrigin.Begin)
-                RaiseEvent FileStreamCreated()
-
-                'Debug.Print("Saved: " & Now().ToString)
-                Me.ExitOK = True
-                'Disposing...
-                Me.ZipIn = Nothing
-                Me.ZipInOK = False
-            Catch ex As Exception
-                'Debug.Print("NOT Saved: " & Now().ToString)
-                Me.ExitOK = False
-            End Try
-            Return Me.ExitOK
-        End Function
-
-        Public Function CompressToStream(ByVal Files As List(Of FileInfo), ByRef TargetStream As IO.Stream) As Boolean
-            If Files.Count = 0 Then Return True
-            If Me.ZipInOK = False Then Call InitZipIn(Me._ArchiveFormat)
-
-            If IsNothing(TargetStream) = True Then
-                TargetStream = New MemoryStream
-            End If
-            Me.ZipIn.CompressionMode = CompressionMode.Create
-            Dim FilePaths As String() = New String() {}
-            Try
-                Dim FilesVerified As FileInfo() = Files.Where(Function(f As FileInfo) f.Exists).ToArray()
-                FilePaths = Array.ConvertAll(Of FileInfo, String)(FilesVerified, FileInfo_to_Filepaths_Converter())
-                If Me._ArchivePassword = "" Then
-                    Me.ZipIn.CompressFiles(TargetStream, FilePaths)
-                Else
-                    Me.ZipIn.EncryptHeaders = True
-                    Me.ZipIn.ZipEncryptionMethod = ZipEncryptionMethod.Aes256
-                    Me.ZipIn.CompressFilesEncrypted(TargetStream, Me._ArchivePassword, FilePaths)
-                End If
-                TargetStream.Seek(0, SeekOrigin.Begin)
-
-                'Debug.Print("Saved: " & Now().ToString)
-                Me.ExitOK = True
-                'Disposing...
-                Me.ZipIn = Nothing
-                Me.ZipInOK = False
-            Catch ex As Exception
-                'Debug.Print("NOT Saved: " & Now().ToString)
-                OCMS.debug_log("IntranetController zip", ex, data:=New With {.filepaths = FilePaths})
-                Me.ExitOK = False
-            End Try
-            Return Me.ExitOK
-        End Function
-
-
-        Public Function CompressToStream(ByVal Files As Dictionary(Of String, IO.Stream)) As Boolean
-            If Files.Count = 0 Then Return True
-            If Me.ZipInOK = False Then Call InitZipIn(Me._ArchiveFormat)
-
-            If IsNothing(_ArchiveFileStream) Then  'nur wenn der interne leer ist...
-                Me.ZipIn.CompressionMode = CompressionMode.Create
-                Me._ArchiveFileStream = New MemoryStream
-            Else
-                Me.ZipIn.CompressionMode = CompressionMode.Append
-            End If
-
-            Try
-                If Me._ArchivePassword = "" Then
-                    Me.ZipIn.CompressStreamDictionary(streamDictionary:=Files, Me._ArchiveFileStream)
-                Else
-                    Me.ZipIn.EncryptHeaders = True
-                    Me.ZipIn.ZipEncryptionMethod = ZipEncryptionMethod.Aes256
-                    Me.ZipIn.CompressStreamDictionary(streamDictionary:=Files, Me._ArchiveFileStream, password:=Me._ArchivePassword)
-                End If
-                Me._ArchiveFileStream.Seek(0, SeekOrigin.Begin)
-                RaiseEvent FileStreamCreated()
-
-                'Debug.Print("Saved: " & Now().ToString)
-                Me.ExitOK = True
-                'Disposing...
-                Me.ZipIn = Nothing
-                Me.ZipInOK = False
-            Catch ex As Exception
-                'Debug.Print("NOT Saved: " & Now().ToString)
-                Me.ExitOK = False
-            End Try
-            Return Me.ExitOK
-        End Function
-        Public Function CompressToStream(ByVal Files As Dictionary(Of String, Byte()), Optional targetstream As IO.Stream = Nothing) As Boolean
-            If Files.Count = 0 Then Return True
-            If Me.ZipInOK = False Then Call InitZipIn(Me._ArchiveFormat)
-
-            If IsNothing(_ArchiveFileStream) Then  'nur wenn der interne leer ist...
-                Me.ZipIn.CompressionMode = CompressionMode.Create
-                Me._ArchiveFileStream = New MemoryStream
-            Else
-                Me.ZipIn.CompressionMode = CompressionMode.Append
-            End If
-
-            Try
-                Dim FilesStreams As New Dictionary(Of String, IO.Stream)
-                For Each fy As String In Files.Keys
-                    FilesStreams.Add(fy, New IO.MemoryStream(Files(fy)))
-                Next
-
-                If Me._ArchivePassword = "" Then
-                    Me.ZipIn.CompressStreamDictionary(streamDictionary:=FilesStreams, If(IsNothing(targetstream), Me._ArchiveFileStream, targetstream))
-                Else
-                    Me.ZipIn.EncryptHeaders = True
-                    Me.ZipIn.ZipEncryptionMethod = ZipEncryptionMethod.Aes256
-                    Me.ZipIn.CompressStreamDictionary(streamDictionary:=FilesStreams, If(IsNothing(targetstream), Me._ArchiveFileStream, targetstream), password:=Me._ArchivePassword)
-                End If
-                Me._ArchiveFileStream.Seek(0, SeekOrigin.Begin)
-                RaiseEvent FileStreamCreated()
-
-                'Debug.Print("Saved: " & Now().ToString)
-                Me.ExitOK = True
-                'Disposing...
-                Me.ZipIn = Nothing
-                Me.ZipInOK = False
-            Catch ex As Exception
-                'Debug.Print("NOT Saved: " & Now().ToString)
-                Me.ExitOK = False
-            End Try
-            Return Me.ExitOK
-        End Function
-
-
-        Public Function WriteArchiveStreamToDisk(Optional ByVal ArchiveFile As IO.FileInfo = Nothing) As Boolean
-            Try
-                If Me._ArchiveFile.Exists() Then Me._ArchiveFile.Delete()
-            Catch ex As Exception
-            End Try
-            If IsNothing(ArchiveFile) = False Then   'Wenn ein DateiPfad hier übergeben wurde...
-                WriteStreamToDisk(Me._ArchiveFileStream, ArchiveFile.FullName)
-            Else  ' sonst wird der interne genommen
-                WriteStreamToDisk(Me._ArchiveFileStream, Me._ArchiveFile.FullName)
-            End If
-            Return Me._ArchiveFile.Exists
-        End Function
-
-
-
-        'Private ArchiveMail As EMail = Nothing
-        'Public Function SendZip(Optional ByVal Subject As String = Nothing, Optional ByVal BodyText As String = Nothing) As Boolean
-        '    Try
-        '        If ArchiveMail Is Nothing Then Exit Function
-        '        If Not Subject = Nothing Then
-        '            ArchiveMail.Subject = Subject
-        '        End If
-        '        If Not BodyText = Nothing Then
-        '            ArchiveMail.Body = BodyText
-        '        End If
-        '        'Send with archive as attachment
-        '        Return ArchiveMail.Send(_ArchivePath.Path)
-        '    Catch ex As Exception
-        '        Return False
-        '    End Try
-        'End Function
-        'Public Function SendZipStream(Optional ByVal Subject As String = Nothing, Optional ByVal BodyText As String = Nothing) As Boolean
-        '    Try
-        '        If ArchiveMail Is Nothing Then Exit Function
-        '        If Not Subject = Nothing Then
-        '            ArchiveMail.Subject = Subject
-        '        End If
-        '        If Not BodyText = Nothing Then
-        '            ArchiveMail.Body = BodyText
-        '        End If
-        '        'Send with archive as attachment
-        '        Return ArchiveMail.Send(_ArchivePath.Name, _ArchiveFileStream)
-        '    Catch ex As Exception
-        '        Return False
-        '    End Try
-        'End Function
-        'Public Sub SetMailSettings(ByVal SMTP As MailServer_Settings, ByVal MAIL As Mail_Settings)
-        '    ArchiveMail = New EMail(SMTP, MAIL)
-        'End Sub
-
-
-#Region "IDisposable Support"
-        Private disposedValue As Boolean ' To detect redundant calls
-
-        ' IDisposable
-        Protected Overridable Sub Dispose(disposing As Boolean)
-            If Not disposedValue Then
-                If disposing Then
-                    ' TODO: dispose managed state (managed objects).
-                    Try
-                        If IsNothing(Me._ArchiveFileStream) = False Then Me._ArchiveFileStream.Dispose()
-                        If IsNothing(Me.ZipOut) = False Then Me.ZipOut.Dispose()
-                        Me.ZipIn = Nothing
-                    Catch ex As Exception
-
-                    End Try
-                End If
-
-                ' TODO: free unmanaged resources (unmanaged objects) and override Finalize() below.
-                ' TODO: set large fields to null.
-            End If
-            disposedValue = True
-        End Sub
-
-        ' TODO: override Finalize() only if Dispose(disposing As Boolean) above has code to free unmanaged resources.
-        'Protected Overrides Sub Finalize()
-        '    ' Do not change this code.  Put cleanup code in Dispose(disposing As Boolean) above.
-        '    Dispose(False)
-        '    MyBase.Finalize()
-        'End Sub
-
-        ' This code added by Visual Basic to correctly implement the disposable pattern.
-        Public Sub Dispose() Implements IDisposable.Dispose
-            ' Do not change this code.  Put cleanup code in Dispose(disposing As Boolean) above.
-            Dispose(True)
-            ' TODO: uncomment the following line if Finalize() is overridden above.
-            ' GC.SuppressFinalize(Me)
-        End Sub
-#End Region
-
-
-    End Class
-
-
-    Public Module Zipping
-
-        Public SevenZipPath As String = ""
-
-        Public Sub FastAppend(ByVal FileToZip As FileInfo, ByVal ArchiveFile As FileInfo)
-            If FileToZip.Exists AndAlso IsNothing(ArchiveFile) = False AndAlso ArchiveFile.Exists Then
-                Dim Zip As New Archive(ArchiveFile) With {
-                    .ZipAppend = True
-                }
-                Dim FL As New List(Of String) From {
-                    FileToZip.FullName
-                }
-                Zip.Compress(FL)
-            End If
-        End Sub
-        Public Sub FastAppend(ByVal FileToZip As FileInfo, ByVal TgtArchiveDirectory As DirectoryInfo, ByVal ArchiveName As String)
-            Dim ArchiveFile As New FileInfo(TgtArchiveDirectory.FullName & If(Strings.Right(TgtArchiveDirectory.FullName, 1) = "\", "", "\") & ArchiveName)
-            If ArchiveFile.Exists Then Call FastAppend(FileToZip, ArchiveFile:=ArchiveFile)
-        End Sub
-        Public Sub FastAppend(ByVal FileToZip As FileInfo, ByVal TgtArchiveDirectoryPath As String, ByVal ArchiveName As String)
-            Dim ArchiveFile As New FileInfo(TgtArchiveDirectoryPath & If(Strings.Right(TgtArchiveDirectoryPath, 1) = "\", "", "\") & ArchiveName)
-            If ArchiveFile.Exists Then Call FastAppend(FileToZip, ArchiveFile:=ArchiveFile)
-        End Sub
-        Public Function FastZip(ByVal DirectoryToZip As DirectoryInfo, Optional ByVal Append As Boolean = True) As IO.FileInfo
-            If DirectoryToZip.Exists Then
-                Dim ZipFile As New FileInfo(DirectoryToZip.Name + ".7z"), cnt As Integer = 0
-                If Append = False Then
-                    Do Until ZipFile.Exists = False
-                        cnt += 1
-                        ZipFile = New FileInfo(DirectoryToZip.Name & "_" & CStr(cnt) & ".7z")
-                    Loop
-                End If
-                Dim Zip As New Archive(ZipFile) With {
-                        .ZipAppend = Append
-                    }
-                Zip.Compress(New List(Of FileInfo)(DirectoryToZip.GetFiles))
-                Return If(ZipFile.Exists, ZipFile, Nothing)
-            Else
-                Return Nothing
-            End If
-        End Function
-        Public Function FastZip(ByVal FileToZip As IO.FileInfo, Optional ByVal Append As Boolean = True) As IO.FileInfo
-            If FileToZip.Exists Then
-                Dim ZipFile As New FileInfo(FileToZip.Name.Replace("." & FileToZip.Extension, "") + ".7z"), cnt As Integer = 0
-                If Append = False Then
-                    Do Until ZipFile.Exists = False
-                        cnt += 1
-                        ZipFile = New FileInfo(FileToZip.Name.Replace("." & FileToZip.Extension, "") & "_" & CStr(cnt) & ".7z")
-                    Loop
-                End If
-                Dim Zip As New Archive(ZipFile) With {
-                    .ZipAppend = Append
-                }
-                Dim FL As New List(Of FileInfo) From {
-                    FileToZip
-                }
-                Zip.Compress(FL)
-                Return If(ZipFile.Exists, ZipFile, Nothing)
-            Else
-                Return Nothing
-            End If
-        End Function
-        Public Function FastZip(ByVal TgtDirectory As String, ByVal Filename As String, Optional ByVal Append As Boolean = True) As IO.FileInfo
-            Return FastZip(New FileInfo(TgtDirectory & If(Strings.Right(TgtDirectory, 1) = "\", "", "\") & Filename), Append)
-        End Function
-
-
-
-
-    End Module
-
-End Namespace

DataService_Legacy/install.bat

@@ -1 +0,0 @@
-Fuchs_Dataservice.exe install --autostart

DataService_Legacy/packages.config

@@ -1,9 +0,0 @@
-<?xml version="1.0" encoding="utf-8"?>
-<packages>
-  <package id="Microsoft.AspNet.Razor" version="3.2.9" targetFramework="net48" />
-  <package id="Microsoft.Web.Infrastructure" version="2.0.0" targetFramework="net48" />
-  <package id="Newtonsoft.Json" version="13.0.3" targetFramework="net48" />
-  <package id="Squid-Box.SevenZipSharp" version="1.6.1.23" targetFramework="net48" />
-  <package id="System.Runtime.InteropServices.RuntimeInformation" version="4.3.0" targetFramework="net48" />
-  <package id="Topshelf" version="4.3.0" targetFramework="net48" />
-</packages>

DataService_Legacy/un-install.bat

@@ -1 +0,0 @@
-Fuchs_Dataservice.exe uninstall

Fuchs.Tests/AssemblyPlatform.cs

@@ -0,0 +1,3 @@
+using System.Runtime.Versioning;
+
+[assembly: SupportedOSPlatform("windows")]

Fuchs.Tests/BankingTests.cs

@@ -129,4 +129,51 @@ public class BankingParseToDatatableTests
         var ex = Record.Exception(() => Svc.ParseToDatatable(stream));
         Assert.Null(ex);
     }
+
+    [Theory]
+    [InlineData("AccountIdentification", 50)]
+    [InlineData("NameOfPayer", 140)]
+    [InlineData("SepaRemittanceInformation", 200)]
+    [InlineData("DebitCreditMark", 2)]
+    [InlineData("UnstructuredData", 390)]
+    public void ParseToDatatable_DefaultSchema_EnforcesKnownColumnWidth(string column, int expectedMaxLength)
+    {
+        using var stream = ToStream(MinimalMT940);
+        var table = Svc.ParseToDatatable(stream);
+        Assert.Equal(expectedMaxLength, table.Columns[column]!.MaxLength);
+    }
+
+    [Fact]
+    public void ParseToDatatable_SchemaWithoutMaxLength_StillEnforcesKnownWidths()
+    {
+        // Mirrors the real bug: SELECT TOP(0) * FROM @tmp (a table-type variable) comes back
+        // from ADO.NET with MaxLength = -1 for every string column, so a schema built purely
+        // from that fetch cannot truncate on its own. ApplyKnownColumnWidths must patch it up
+        // regardless of what the caller-supplied schema carries.
+        var schema = new DataTable();
+        schema.Columns.Add("AccountIdentification", typeof(string));
+        schema.Columns.Add("Amount", typeof(decimal));
+        schema.Columns.Add("DebitCreditMark", typeof(string));
+        Assert.Equal(-1, schema.Columns["AccountIdentification"]!.MaxLength);
+
+        using var stream = ToStream(MinimalMT940);
+        var table = Svc.ParseToDatatable(stream, schemaDatatable: schema);
+
+        Assert.Equal(50, table.Columns["AccountIdentification"]!.MaxLength);
+        Assert.Equal(2, table.Columns["DebitCreditMark"]!.MaxLength);
+    }
+
+    [Fact]
+    public void ParseToDatatable_OverlongAccountIdentification_TruncatesInsteadOfThrowing()
+    {
+        string longAccount = "DE" + new string('9', 60); // 62 chars, over the 50-char column width
+        string mt940 = MinimalMT940.Replace("DE12345678901234567890", longAccount);
+
+        using var stream = ToStream(mt940);
+        var table = Svc.ParseToDatatable(stream);
+
+        Assert.Equal(1, table.Rows.Count);
+        Assert.Equal(50, ((string)table.Rows[0]["AccountIdentification"]).Length);
+        Assert.Equal(longAccount[..50], table.Rows[0]["AccountIdentification"]);
+    }
 }

Fuchs.Tests/CamtParserTests.cs

@@ -377,4 +377,72 @@ public class BankingDualFormatTests
         Assert.Equal("ZIP Sender", t.Rows[0]["NameOfPayer"]);
         Assert.Equal("ZIP Zahlung", t.Rows[0]["SepaRemittanceInformation"]);
     }
+
+    /// <summary>
+    /// Schema whose string columns carry the same MaxLength as the real
+    /// <c>fds__tt__bankingtransactions</c> table type. Building it here lets the tests
+    /// catch width-overflow bugs that <see cref="BankingService.BuildDefaultSchema"/> (which
+    /// uses unconstrained strings) cannot. Only the columns exercised below are constrained.
+    /// </summary>
+    private static DataTable DbLikeSchema()
+    {
+        var t = new DataTable();
+        t.Columns.Add("AccountIdentification", typeof(string)).MaxLength = 50;
+        t.Columns.Add("Amount", typeof(decimal));
+        t.Columns.Add("ValueDate", typeof(DateTime));
+        t.Columns.Add("FundsCode", typeof(string)).MaxLength = 1;   // VARCHAR(1) — currency "EUR" must not land here
+        t.Columns.Add("NameOfPayer", typeof(string)).MaxLength = 140;
+        t.Columns.Add("PostingText", typeof(string)).MaxLength = 30;
+        t.Columns.Add("TransactionTypeIdCode", typeof(string)).MaxLength = 3;
+        t.Columns.Add("SepaRemittanceInformation", typeof(string)).MaxLength = 200;
+        t.Columns.Add("DebitCreditMark", typeof(string)).MaxLength = 2;
+        return t;
+    }
+
+    [Fact]
+    public void ParseToDatatable_Camt_WithDbWidthSchema_StillImportsRows()
+    {
+        // Regression: CAMT wrote the ISO currency ("EUR") into FundsCode (VARCHAR(1)).
+        // Against the real DB widths that overflowed and — swallowed per entry — dropped
+        // every transaction, so nothing reached the database.
+        using var s = ToStream(Camt053);
+        var t = Svc.ParseToDatatable(s, schemaDatatable: DbLikeSchema());
+
+        Assert.Equal(1, t.Rows.Count);
+        Assert.Equal("DE12345678901234567890", t.Rows[0]["AccountIdentification"]);
+        Assert.Equal(500.00m, t.Rows[0]["Amount"]);
+        // Currency is no longer forced into the 1-char FundsCode column.
+        Assert.Equal(DBNull.Value, t.Rows[0]["FundsCode"]);
+    }
+
+    [Fact]
+    public void ParseToDatatable_Camt_OverlongFields_AreTruncatedNotDropped()
+    {
+        // Some banks put the full postal address into <Nm>, not just a name — real-world case
+        // that exceeds even the ISO 20022 Max140Text width this column is now sized to.
+        const string longName = "Ein sehr langer Zahlungspflichtiger Name der weit ueber hundertvierzig Zeichen hinausgeht GmbH Co KG, Musterstrasse 123, 12345 Musterstadt, Deutschland";
+        string camt = """
+            <?xml version="1.0"?>
+            <Document xmlns="urn:iso:std:iso:20022:tech:xsd:camt.053.001.02">
+              <BkToCstmrStmt><Stmt>
+                <Acct><Id><IBAN>DE12345678901234567890</IBAN></Id><Ccy>EUR</Ccy></Acct>
+                <Ntry>
+                  <Amt Ccy="EUR">500.00</Amt><CdtDbtInd>CRDT</CdtDbtInd>
+                  <BookgDt><Dt>2023-01-15</Dt></BookgDt>
+                  <NtryDtls><TxDtls>
+                    <RltdPties><Dbtr><Nm>{NAME}</Nm></Dbtr></RltdPties>
+                    <RmtInf><Ustrd>Rechnung</Ustrd></RmtInf>
+                  </TxDtls></NtryDtls>
+                </Ntry>
+              </Stmt></BkToCstmrStmt>
+            </Document>
+            """.Replace("{NAME}", longName);
+
+        using var s = ToStream(camt);
+        var t = Svc.ParseToDatatable(s, schemaDatatable: DbLikeSchema());
+
+        Assert.Equal(1, t.Rows.Count);
+        Assert.Equal(140, ((string)t.Rows[0]["NameOfPayer"]).Length);   // truncated to column width, row kept
+        Assert.Equal(longName[..140], t.Rows[0]["NameOfPayer"]);
+    }
 }

Fuchs.Tests/DocumentMetadataBuilderTests.cs

@@ -110,6 +110,20 @@ public class DocumentMetadataBuilderTests
         Assert.Equal(guid.ToString(), metadata["file_guid"]);
     }
 
+    [Theory]
+    [InlineData("Zahlungserinnerung für Müller", "Zahlungserinnerung f%C3%BCr M%C3%BCller")]
+    [InlineData("Rechnung\r\nKunde", "Rechnung%0D%0AKunde")]
+    public void Build_NonAsciiOrControlCharacters_PercentEncodesUtf8ForHttpHeaders(
+        string value, string expected)
+    {
+        var row = new Dictionary<string, object?> { ["DocumentName"] = value };
+
+        var metadata = DocumentMetadataBuilder.Build(row, new[] { "DocumentName" });
+
+        Assert.Equal(expected, metadata["DocumentName"]);
+        Assert.All(metadata["DocumentName"], c => Assert.InRange(c, '\u0020', '\u007e'));
+    }
+
     // ── Field-list edge cases ────────────────────────────────────────────────
     [Theory]
     [InlineData("")]

Fuchs.Tests/ERechnungMapperTests.cs

@@ -0,0 +1,192 @@
+using System.Collections.Generic;
+using System.Text;
+using eRechnungLib.Model.CodeLists;
+using eRechnungLib.Profiles;
+using Fuchs.intranet;
+using Fuchs.Services;
+using Newtonsoft.Json.Linq;
+using Xunit;
+using static OCORE.OCORE_dictionaries;
+
+namespace Fuchs.Tests;
+
+/// <summary>
+/// Verifies the FdsInvoiceData → EN 16931 model mapping and the ZUGFeRD (EN 16931) hybrid
+/// production: structured buyer, lines/totals, effortless B2C, and §13b reverse charge. See
+/// ADR 0012.
+/// </summary>
+public class ERechnungMapperTests
+{
+    private static FdsInvoiceData BuildInvoice(string sendToAddressJson, string vat = "19",
+        string invoiceOptions = "", bool withItem = true, string provisionPeriod = "")
+    {
+        var items = withItem
+            ? "[{'id':'900','type':'material','title':'Reparatur','desc':'Vor Ort','qty':2,'price_net':50,'total_net':100,'vat':'" + vat + "'}]"
+            : "[]";
+        var jobj = JObject.Parse("{'req':[{'Id':'1','text':'Auftrag','items':" + items + "}]}");
+        var inv = new FdsInvoiceData(jobj)
+        {
+            InvoiceRegistration = new GenericObjectDictionary(new Dictionary<string, object>
+            {
+                ["Id"]                 = "42",
+                ["InvoiceId"]          = "R2026-0007",
+                ["InvoiceTitle"]       = "Rechnung",
+                ["DateCreated"]        = "2026-07-17 10:00:00",
+                ["InvoiceOptions"]     = invoiceOptions,
+                ["InvoiceBalance_net"] = "100",
+                ["InvoiceVAT_1"]       = vat,
+                ["ProvisionPeriod"]    = provisionPeriod,
+                ["SendToAddressJson"]  = sendToAddressJson,
+            })
+        };
+        return inv;
+    }
+
+    private const string B2BAddress =
+        "{'name':'Muster GmbH','street':'Hauptstr. 1','postalCode':'40223','city':'Düsseldorf','countryCode':'DE','vatId':'DE123456789'}";
+
+    [Fact]
+    public void BuildEInvoice_MapsSellerBuyerAndLines_WithConsistentTotals()
+    {
+        var model = ERechnungMapper.BuildEInvoice(BuildInvoice(B2BAddress)).Model;
+
+        Assert.Equal("Sebastian Fuchs GmbH & Co. KG", model.Seller.Name);
+        Assert.Equal("DE", model.Seller.Address.Country.Value);
+        Assert.Equal("Muster GmbH", model.Buyer.Name);
+        Assert.Equal("40223", model.Buyer.Address.PostalCode);
+        Assert.Equal("DE123456789", model.Buyer.VatId);
+        Assert.Equal("R2026-0007", model.InvoiceNumber);
+
+        var line = Assert.Single(model.Lines);
+        Assert.Equal(100m, line.NetAmount);
+        Assert.Equal(VatCategoryCode.StandardRate, line.VatCategory);
+        Assert.NotNull(model.Totals);
+        Assert.Equal(100m, model.Totals!.TaxExclusiveAmount);
+        Assert.Equal(19m, model.Totals.TaxTotalAmount);
+        Assert.Equal(119m, model.Totals.TaxInclusiveAmount);
+    }
+
+    [Fact]
+    public void ToZugferd_EN16931_ProducesHybridPdfWithEmbeddedCii()
+    {
+        var einvoice = ERechnungMapper.BuildEInvoice(BuildInvoice(B2BAddress));
+        var result = einvoice.ToZugferd(ZugferdProfile.EN16931);
+
+        Assert.True(result.Success);
+        Assert.StartsWith("%PDF", Encoding.ASCII.GetString(result.Value!, 0, 4));
+        // The CII XML is embedded and carries the invoice number.
+        string content = Encoding.Latin1.GetString(result.Value!);
+        Assert.Contains("CrossIndustryInvoice", content);
+        // No PDFA-ICC warning: the bundled sRGB profile is present, so the output intent is set.
+        Assert.DoesNotContain(result.Validation.Warnings, m => m.RuleId == "PDFA-ICC");
+    }
+
+    [Fact]
+    public void PrivatePerson_NoVatId_MapsWithoutBuyerTaxRegistration_AndProducesHybrid()
+    {
+        var b2c = "{'name':'Max Mustermann','street':'Weg 2','postalCode':'50667','city':'Köln','countryCode':'DE'}";
+        var einvoice = ERechnungMapper.BuildEInvoice(BuildInvoice(b2c));
+
+        Assert.Null(einvoice.Model.Buyer.VatId);
+        var result = einvoice.ToZugferd(ZugferdProfile.EN16931);
+        Assert.True(result.Success);
+        Assert.StartsWith("%PDF", Encoding.ASCII.GetString(result.Value!, 0, 4));
+    }
+
+    [Fact]
+    public void ReverseCharge_13b_SetsCategoryAeAndExemptionReason()
+    {
+        var model = ERechnungMapper.BuildEInvoice(BuildInvoice(B2BAddress, vat: "0", invoiceOptions: "§13b")).Model;
+
+        var line = Assert.Single(model.Lines);
+        Assert.Equal(VatCategoryCode.ReverseCharge, line.VatCategory);
+        Assert.Equal(0m, line.VatRate);
+        Assert.True(model.VatExemptionReasons.ContainsKey(VatCategoryCode.ReverseCharge));
+        Assert.Equal(0m, model.Totals!.TaxTotalAmount);
+    }
+
+    [Fact]
+    public void LumpSumInvoice_NoItems_SynthesisesSingleLineFromTotal()
+    {
+        var model = ERechnungMapper.BuildEInvoice(BuildInvoice(B2BAddress, withItem: false)).Model;
+        var line = Assert.Single(model.Lines);
+        Assert.Equal(100m, line.NetAmount);
+        Assert.Equal(119m, model.Totals!.TaxInclusiveAmount);
+    }
+
+    [Theory]
+    [InlineData("DE", "DE")]
+    [InlineData("Deutschland", "DE")]
+    [InlineData("Österreich", "AT")]
+    [InlineData("", "DE")]
+    public void NormalizeCountry_MapsNamesAndCodes(string raw, string expected)
+        => Assert.Equal(expected, ERechnungMapper.NormalizeCountry(raw).Value);
+
+    [Fact]
+    public void ServicePeriod_SingleDate_MapsToDeliveryDate()
+    {
+        var model = ERechnungMapper.BuildEInvoice(BuildInvoice(B2BAddress, provisionPeriod: "18.06.2026")).Model;
+        Assert.NotNull(model.Delivery);
+        Assert.Equal(new System.DateOnly(2026, 6, 18), model.Delivery!.DeliveryDate);
+        Assert.Null(model.InvoicingPeriod);
+    }
+
+    [Fact]
+    public void ServicePeriod_DateRange_MapsToInvoicingPeriod()
+    {
+        var model = ERechnungMapper.BuildEInvoice(BuildInvoice(B2BAddress, provisionPeriod: "01.06.2026 - 30.06.2026")).Model;
+        Assert.NotNull(model.InvoicingPeriod);
+        Assert.Equal(new System.DateOnly(2026, 6, 1), model.InvoicingPeriod!.StartDate);
+        Assert.Equal(new System.DateOnly(2026, 6, 30), model.InvoicingPeriod.EndDate);
+    }
+
+    [Fact]
+    public void Seller_ComesFromSettings_WhenProvided()
+    {
+        var seller = new ERechnungSellerSettings { Name = "Test Handwerk GmbH", VatId = "DE999999999", Iban = "DE00" };
+        var model = ERechnungMapper.BuildEInvoice(BuildInvoice(B2BAddress), seller).Model;
+        Assert.Equal("Test Handwerk GmbH", model.Seller.Name);
+        Assert.Equal("DE999999999", model.Seller.VatId);
+    }
+
+    [Fact]
+    public void B2G_WithLeitwegId_SetsBuyerReference_AndSellerContact()
+    {
+        var b2g = "{'name':'Stadt Düsseldorf','street':'Marktplatz 2','postalCode':'40213','city':'Düsseldorf','countryCode':'DE','leitwegId':'05111-12345-67'}";
+        var model = ERechnungMapper.BuildEInvoice(BuildInvoice(b2g)).Model;
+
+        Assert.Equal("05111-12345-67", model.BuyerReference);          // BT-10 (Leitweg-ID)
+        Assert.NotNull(model.Seller.ElectronicAddress);                // BT-34 (XRechnung)
+        Assert.NotNull(model.Seller.Contact);                          // BG-6 (BR-DE-5/6/7)
+        Assert.Equal("info@sanitaerfuchs.de", model.Seller.Contact!.Email);
+    }
+
+    [Fact]
+    public void B2B_NoLeitwegId_LeavesBuyerReferenceUnset()
+    {
+        var model = ERechnungMapper.BuildEInvoice(BuildInvoice(B2BAddress)).Model;
+        Assert.True(string.IsNullOrEmpty(model.BuyerReference));
+    }
+
+    [Fact]
+    public void Seller_HasVatIdAndPaymentTerms_ForBrCo25AndBrCo26()
+    {
+        var model = ERechnungMapper.BuildEInvoice(BuildInvoice(B2BAddress)).Model;
+        // BR-CO-26: seller VAT id (BT-31) present, in addition to the Steuernummer (BT-32).
+        Assert.Equal("DE286366012", model.Seller.VatId);
+        // BR-CO-25: payment terms (BT-20) / due date (BT-9) present for a positive amount due.
+        Assert.NotNull(model.PaymentTerms);
+        Assert.False(string.IsNullOrWhiteSpace(model.PaymentTerms!.Description));
+    }
+
+    [Fact]
+    public void B2G_ToZugferdXRechnung_ProducesHybridWithXRechnungCustomization()
+    {
+        var b2g = "{'name':'Stadt Düsseldorf','street':'Marktplatz 2','postalCode':'40213','city':'Düsseldorf','countryCode':'DE','leitwegId':'05111-12345-67'}";
+        var result = ERechnungMapper.BuildEInvoice(BuildInvoice(b2g)).ToZugferd(ZugferdProfile.XRechnung);
+
+        Assert.True(result.Success);
+        string content = System.Text.Encoding.Latin1.GetString(result.Value!);
+        Assert.Contains("xrechnung_3.0", content);   // XRechnung 3.0 CIUS customization id
+    }
+}

Fuchs.Tests/ERechnungValidatorTests.cs

@@ -0,0 +1,114 @@
+using System;
+using System.Net;
+using System.Net.Http;
+using System.Threading;
+using System.Threading.Tasks;
+using Fuchs.Services;
+using Microsoft.Extensions.Logging.Abstractions;
+using Microsoft.Extensions.Options;
+using Xunit;
+
+namespace Fuchs.Tests;
+
+/// <summary>
+/// Exercises the external eRechnung validator client against a stubbed HTTP endpoint: response
+/// parsing, the not-configured short-circuit, and unreachable/error handling (never throws).
+/// </summary>
+public class ERechnungValidatorTests
+{
+    private sealed class StubHandler : HttpMessageHandler
+    {
+        private readonly HttpStatusCode _status;
+        private readonly string _body;
+        public HttpRequestMessage? Last;
+        public StubHandler(HttpStatusCode status, string body) { _status = status; _body = body; }
+        protected override Task<HttpResponseMessage> SendAsync(HttpRequestMessage request, CancellationToken ct)
+        {
+            Last = request;
+            return Task.FromResult(new HttpResponseMessage(_status) { Content = new StringContent(_body) });
+        }
+    }
+
+    private sealed class StubFactory : IHttpClientFactory
+    {
+        private readonly HttpMessageHandler _handler;
+        public StubFactory(HttpMessageHandler handler) => _handler = handler;
+        public HttpClient CreateClient(string name) => new(_handler, disposeHandler: false);
+    }
+
+    private static ProcessWebERechnungValidator Make(HttpMessageHandler handler, bool enabled = true,
+        string url = "https://validator.test/api/eInvoice")
+    {
+        var settings = Options.Create(new ERechnungSettings
+        {
+            Validation = new ERechnungValidationSettings { Enabled = enabled, ServiceUrl = url }
+        });
+        return new ProcessWebERechnungValidator(new StubFactory(handler), settings,
+            NullLogger<ProcessWebERechnungValidator>.Instance);
+    }
+
+    [Fact]
+    public async Task ValidatePdf_BothPass_ReturnsIsValid()
+    {
+        var handler = new StubHandler(HttpStatusCode.OK,
+            "{\"isValid\":true,\"summary\":\"ok\",\"xml\":{\"isValid\":true},\"pdfa\":{\"isCompliant\":true}}");
+        var result = await Make(handler).ValidatePdfAsync(new byte[] { 1, 2, 3 });
+
+        Assert.True(result.IsValid);
+        Assert.True(result.XmlValid);
+        Assert.True(result.PdfACompliant);
+        Assert.EndsWith("/validatepdf", handler.Last!.RequestUri!.ToString());
+        Assert.Equal("application/pdf", handler.Last.Content!.Headers.ContentType!.MediaType);
+    }
+
+    [Theory]
+    [InlineData("{\"xml\":{\"isValid\":false,\"errorCount\":3},\"pdfa\":{\"isCompliant\":true}}", false, true)]
+    [InlineData("{\"xml\":{\"isValid\":true},\"pdfa\":{\"isCompliant\":false}}", true, false)]
+    public async Task ValidatePdf_PartialFailure_IsNotValid(string body, bool xml, bool pdfa)
+    {
+        var result = await Make(new StubHandler(HttpStatusCode.OK, body)).ValidatePdfAsync(new byte[] { 1 });
+        Assert.False(result.IsValid);
+        Assert.Equal(xml, result.XmlValid);
+        Assert.Equal(pdfa, result.PdfACompliant);
+        Assert.True(result.HasHardError); // real PDF/A or XML errors are hard failures
+    }
+
+    [Fact]
+    public async Task ValidatePdf_PdfAOk_ButXmlScenarioNotMatched_IsNotHardError()
+    {
+        // EN 16931 ZUGFeRD checked by an XRechnung-only scenario set: PDF/A compliant, XML rejected
+        // with zero errors → not strictly valid, but not a hard error (must not withhold the invoice).
+        var body = "{\"xml\":{\"isValid\":false,\"scenarioMatched\":false,\"errorCount\":0},\"pdfa\":{\"isCompliant\":true}}";
+        var result = await Make(new StubHandler(HttpStatusCode.OK, body)).ValidatePdfAsync(new byte[] { 1 });
+
+        Assert.True(result.PdfACompliant);
+        Assert.False(result.ScenarioMatched);
+        Assert.False(result.IsValid);
+        Assert.False(result.HasHardError);
+    }
+
+    [Fact]
+    public async Task ValidatePdf_Disabled_ReturnsNotConfigured()
+    {
+        var result = await Make(new StubHandler(HttpStatusCode.OK, "{}"), enabled: false).ValidatePdfAsync(new byte[] { 1 });
+        Assert.False(result.Configured);
+        Assert.False(result.IsValid);
+    }
+
+    [Fact]
+    public async Task ValidatePdf_ServerError_IsReachedFalse_AndDoesNotThrow()
+    {
+        var result = await Make(new StubHandler(HttpStatusCode.BadGateway, "validator down")).ValidatePdfAsync(new byte[] { 1 });
+        Assert.False(result.Reached);
+        Assert.False(result.IsValid);
+    }
+
+    [Fact]
+    public async Task ValidatePdf_Enabled_RequiresNonEmptyUrl()
+    {
+        var v = Make(new StubHandler(HttpStatusCode.OK, "{}"), url: "");
+        Assert.False(v.Enabled);
+        var result = await v.ValidatePdfAsync(new byte[] { 1 });
+        Assert.False(result.Configured);
+    }
+}

Fuchs.Tests/EventServiceTests.cs

@@ -0,0 +1,121 @@
+using System.Collections.Generic;
+using System.Threading;
+using System.Threading.Tasks;
+using Fuchs.Notifications;
+using Microsoft.AspNetCore.SignalR;
+using Microsoft.Extensions.Logging.Abstractions;
+using Xunit;
+
+namespace Fuchs.Tests;
+
+/// <summary>
+/// Tests for <see cref="EventService"/>, the single point every server-side
+/// operation goes through to notify the user. Covers the two failure methods the
+/// exception safety nets rely on (<c>UserIssueAsync</c> from
+/// <c>IntranetController.Do</c>'s catch-all, and <c>InvoiceIssueAsync</c> from
+/// <c>HandleInvoiceGet</c>) rendering as <c>"error"</c> notifications, plus a
+/// contrasting success path rendering as <c>"info"</c> — see ADR 0003.
+/// </summary>
+public class EventServiceTests
+{
+    // ── Test doubles: capture the GuiNotification pushed to Clients.All ─────────
+    private sealed class CapturingClientProxy : IClientProxy
+    {
+        public string? Method { get; private set; }
+        public object?[]? Args { get; private set; }
+
+        public Task SendCoreAsync(string method, object?[] args, CancellationToken cancellationToken = default)
+        {
+            Method = method;
+            Args = args;
+            return Task.CompletedTask;
+        }
+    }
+
+    private sealed class StubHubClients : IHubClients
+    {
+        private readonly IClientProxy _all;
+        public StubHubClients(IClientProxy all) => _all = all;
+        public IClientProxy All => _all;
+        public IClientProxy AllExcept(IReadOnlyList<string> excludedConnectionIds) => throw new System.NotImplementedException();
+        public IClientProxy Client(string connectionId) => throw new System.NotImplementedException();
+        public IClientProxy Clients(IReadOnlyList<string> connectionIds) => throw new System.NotImplementedException();
+        public IClientProxy Group(string groupName) => throw new System.NotImplementedException();
+        public IClientProxy Groups(IReadOnlyList<string> groupNames) => throw new System.NotImplementedException();
+        public IClientProxy GroupExcept(string groupName, IReadOnlyList<string> excludedConnectionIds) => throw new System.NotImplementedException();
+        public IClientProxy User(string userId) => throw new System.NotImplementedException();
+        public IClientProxy Users(IReadOnlyList<string> userIds) => throw new System.NotImplementedException();
+    }
+
+    private sealed class StubHubContext : IHubContext<NotificationHub>
+    {
+        public StubHubContext(IHubClients clients) => Clients = clients;
+        public IHubClients Clients { get; }
+        public IGroupManager Groups => throw new System.NotImplementedException();
+    }
+
+    private static (EventService svc, CapturingClientProxy proxy) CreateService()
+    {
+        var proxy = new CapturingClientProxy();
+        var hub = new StubHubContext(new StubHubClients(proxy));
+        return (new EventService(hub, NullLogger<EventService>.Instance), proxy);
+    }
+
+    private static GuiNotification Captured(CapturingClientProxy proxy)
+    {
+        Assert.Equal("notification", proxy.Method);
+        Assert.NotNull(proxy.Args);
+        var arg = Assert.Single(proxy.Args!);
+        return Assert.IsType<GuiNotification>(arg);
+    }
+
+    // ── Failure paths the exception safety nets use ─────────────────────────────
+    [Fact]
+    public async Task UserIssueAsync_PublishesErrorNotificationWithMessage()
+    {
+        var (svc, proxy) = CreateService();
+
+        await svc.UserIssueAsync(
+            "Aktion fehlgeschlagen",
+            "Die Aktion konnte aufgrund eines unerwarteten Fehlers nicht abgeschlossen werden. Bitte versuchen Sie es erneut.",
+            "user-42",
+            new Dictionary<string, object?> { ["fn"] = "inv" });
+
+        var n = Captured(proxy);
+        Assert.Equal("error", n.Severity);
+        Assert.Equal("Aktion fehlgeschlagen", n.Title);
+        Assert.Equal(DomainEventType.UserIssue.ToString(), n.Type);
+        Assert.Contains("nicht abgeschlossen werden", n.Message);
+        Assert.Equal("inv", n.Context["fn"]);
+    }
+
+    [Fact]
+    public async Task InvoiceIssueAsync_PublishesErrorNotificationCarryingInvoiceId()
+    {
+        var (svc, proxy) = CreateService();
+
+        await svc.InvoiceIssueAsync(
+            "Die Rechnung konnte aufgrund eines Fehlers nicht geladen werden.",
+            "user-42",
+            "INV-1001");
+
+        var n = Captured(proxy);
+        Assert.Equal("error", n.Severity);
+        Assert.Equal(DomainEventType.InvoiceCreationFailed.ToString(), n.Type);
+        Assert.Equal("Die Rechnung konnte aufgrund eines Fehlers nicht geladen werden.", n.Message);
+        Assert.Equal("INV-1001", n.Context["id"]);
+    }
+
+    // ── Contrasting success path renders as info, not error ─────────────────────
+    [Fact]
+    public async Task InvoiceMarkedSentAsync_PublishesInfoNotification()
+    {
+        var (svc, proxy) = CreateService();
+
+        await svc.InvoiceMarkedSentAsync("INV-1001", "R2026-0001", "user-42");
+
+        var n = Captured(proxy);
+        Assert.Equal("info", n.Severity);
+        Assert.Contains("R2026-0001", n.Message);
+    }
+}

Fuchs.Tests/FdsDataServiceTests.cs

@@ -0,0 +1,446 @@
+using System;
+using System.Collections.Generic;
+using System.Data;
+using System.Globalization;
+using System.IO;
+using System.Linq;
+using System.Text;
+using System.Xml;
+using fds;
+using Microsoft.Extensions.Configuration;
+using Microsoft.Extensions.Logging.Abstractions;
+using Xunit;
+
+namespace Fuchs.Tests;
+
+// ─────────────────────────────────────────────────────────────────────────────
+// Tests for the Fuchs_DataService library (MFR ERP sync).
+//
+// Since Topshelf/own-config were removed and the library is hosted in-process by
+// Fuchs, these tests exercise the parts that are pure/deterministic and do not
+// require a live SQL Server or MFR endpoint: DATEV header/CSV/XML formatting,
+// UpdateNeed parsing, the FdsShared utility helpers, config resolution, and the
+// (network-free) FdsMfrClient construction.
+// ─────────────────────────────────────────────────────────────────────────────
+
+/// <summary>DATEV header line formatting — pure string assembly, no I/O.</summary>
+public class DatevHeaderTests
+{
+    [Fact]
+    public void ToHeaderString_Defaults_ProducesThirtySemicolonFields()
+    {
+        var header = new DatevHeader();
+        var parts = header.ToHeaderString().Split(';');
+
+        Assert.Equal(30, parts.Length);
+        Assert.Equal("\"EXTF\"", parts[0]);   // Kennzeichen quoted
+        Assert.Equal("700", parts[1]);         // Versionsnummer
+        Assert.Equal("1", parts[20]);          // Festschreibung true → "1"
+        Assert.Equal("\"EUR\"", parts[21]);    // WKZ quoted
+    }
+
+    [Fact]
+    public void ToHeaderString_MapsNumericAndDateFields()
+    {
+        var header = new DatevHeader
+        {
+            Beraternummer = 12345,
+            Mandantennummer = 678,
+            Sachkontenlänge = 4,
+            WJBeginn = new DateTime(2026, 1, 1),
+            DatumVon = new DateTime(2026, 7, 1),
+            DatumBis = new DateTime(2026, 7, 31),
+            Bezeichnung = "fds_m260731",
+        };
+        var parts = header.ToHeaderString().Split(';');
+
+        Assert.Equal("12345", parts[10]);
+        Assert.Equal("678", parts[11]);
+        Assert.Equal("20260101", parts[12]);
+        Assert.Equal("4", parts[13]);
+        Assert.Equal("20260701", parts[14]);
+        Assert.Equal("20260731", parts[15]);
+        Assert.Equal("\"fds_m260731\"", parts[16]);
+    }
+
+    [Theory]
+    [InlineData(true, "1")]
+    [InlineData(false, "0")]
+    public void ToHeaderString_Festschreibung_MapsToFlag(bool festschreibung, string expected)
+    {
+        var header = new DatevHeader { Festschreibung = festschreibung };
+        Assert.Equal(expected, header.ToHeaderString().Split(';')[20]);
+    }
+
+    [Fact]
+    public void ToHeaderString_DtvfKennzeichen_IsHonoured()
+    {
+        var header = new DatevHeader { Kennzeichen = DatevKennzeichen.DTVF };
+        Assert.Equal("\"DTVF\"", header.ToHeaderString().Split(';')[0]);
+    }
+
+    [Theory]
+    [InlineData(DatevFormatkategorie.Debitoren__Kreditoren, "Debitoren/Kreditoren")]
+    [InlineData(DatevFormatkategorie.Buchungsstapel, "Buchungsstapel")]
+    [InlineData(DatevFormatkategorie.Wiederkehrende_Buchungen, "Wiederkehrende Buchungen")]
+    public void Formatname_TranslatesEnumUnderscores(DatevFormatkategorie kat, string expected)
+    {
+        var header = new DatevHeader { Formatkategorie = kat };
+        Assert.Equal(expected, header.Formatname);
+        // Field 3 embeds the same, quoted.
+        Assert.Equal($"\"{expected}\"", header.ToHeaderString().Split(';')[3]);
+    }
+}
+
+/// <summary>DATEV CSV + document XML generation on FdsMfr (no DB / no MFR).</summary>
+public class FdsMfrDatevTests
+{
+    private static FdsMfr NewMfr() =>
+        new(NullLogger<FdsMfr>.Instance, NullLoggerFactory.Instance);
+
+    [Fact]
+    public void DATEV_PrependsHeaderLine_AndSemicolonCsvWithColumnHeaders()
+    {
+        var header = new DatevHeader { Bezeichnung = "test" };
+        var tbl = new DataTable();
+        tbl.Columns.Add("Konto", typeof(string));
+        tbl.Columns.Add("Betrag", typeof(decimal));
+        tbl.Rows.Add("1200", 119.50m);
+
+        var result = NewMfr().DATEV(header, tbl);
+        var lines = result.Split("\r\n");
+
+        Assert.Equal(header.ToHeaderString(), lines[0]);   // header line first
+        Assert.Equal("Konto;Betrag", lines[1]);            // column headers, semicolon-delimited, unquoted
+        Assert.Contains("1200", lines[2]);
+        // de-DE culture → decimal comma
+        Assert.Contains("119,5", lines[2]);
+    }
+
+    // Note: only the root <archive> is in the DATEV namespace; the generator emits child
+    // elements in the empty namespace (existing production behavior). Child lookups therefore
+    // use namespace-agnostic local-name() XPath rather than the datev namespace prefix.
+
+    [Fact]
+    public void CreateDatevDocumentXml_BuildsArchiveWithNamespaceAndOneDocumentPerInput()
+    {
+        var docs = new List<DatevDocument>
+        {
+            new("guid-1", "invoice1.pdf", "RgNr: 100", "ProcessWeb_Belege", "2026/07"),
+            new("guid-2", "invoice2.pdf", "",          "ProcessWeb_Belege", "2026/07"),
+        };
+
+        var xml = NewMfr().CreateDatevDocumentXml(docs);
+        var doc = new XmlDocument();
+        doc.LoadXml(xml);
+
+        Assert.Equal("archive", doc.DocumentElement!.LocalName);
+        Assert.Equal("http://xml.datev.de/bedi/tps/document/v04.0", doc.DocumentElement.NamespaceURI);
+        Assert.Equal("ProcessWeb", doc.DocumentElement.GetAttribute("generatingSystem"));
+        Assert.Equal("4.0", doc.DocumentElement.GetAttribute("version"));
+
+        Assert.NotNull(doc.SelectSingleNode("//*[local-name()='header']/*[local-name()='date']"));
+        Assert.NotNull(doc.SelectSingleNode("//*[local-name()='header']/*[local-name()='description']"));
+
+        var documentNodes = doc.SelectNodes("//*[local-name()='content']/*[local-name()='document']");
+        Assert.Equal(2, documentNodes!.Count);
+    }
+
+    [Fact]
+    public void CreateDatevDocumentXml_OmitsKeywordsWhenEmpty_IncludesWhenPresent()
+    {
+        var docs = new List<DatevDocument>
+        {
+            new("g-withkw", "a.pdf", "keyword-here", "ProcessWeb_Belege", "2026/07"),
+            new("g-nokw",   "b.pdf", "",             "ProcessWeb_Belege", "2026/07"),
+        };
+
+        var doc = new XmlDocument();
+        doc.LoadXml(NewMfr().CreateDatevDocumentXml(docs));
+
+        var withKw = doc.SelectSingleNode("//*[local-name()='document'][@guid='g-withkw']")!;
+        var noKw = doc.SelectSingleNode("//*[local-name()='document'][@guid='g-nokw']")!;
+
+        var withKwNode = withKw.SelectSingleNode("*[local-name()='keywords']");
+        Assert.NotNull(withKwNode);
+        Assert.Equal("keyword-here", withKwNode.InnerText);
+        Assert.Null(noKw.SelectSingleNode("*[local-name()='keywords']"));
+    }
+
+    [Fact]
+    public void CreateDatevDocumentXml_EmitsThreeRepositoryLevels()
+    {
+        var docs = new List<DatevDocument>
+        {
+            new("g1", "a.pdf", "", "ProcessWeb_Belege", "2026/07_w03"),
+        };
+        var doc = new XmlDocument();
+        doc.LoadXml(NewMfr().CreateDatevDocumentXml(docs));
+
+        var levels = doc.SelectNodes(
+            "//*[local-name()='document']/*[local-name()='repository']/*[local-name()='level']")!;
+        Assert.Equal(3, levels.Count);
+        Assert.Equal("ProcessWeb", ((XmlElement)levels[0]!).GetAttribute("name"));
+        Assert.Equal("ProcessWeb_Belege", ((XmlElement)levels[1]!).GetAttribute("name"));
+        Assert.Equal("2026/07_w03", ((XmlElement)levels[2]!).GetAttribute("name"));
+    }
+}
+
+/// <summary>FdsMfr.UpdateNeed parsing + enum contract.</summary>
+public class FdsMfrUpdateNeedTests
+{
+    [Theory]
+    [InlineData("Reset", FdsMfr.UpdateNeed.Reset)]
+    [InlineData("Full", FdsMfr.UpdateNeed.Full)]
+    [InlineData("Short", FdsMfr.UpdateNeed.Short)]
+    [InlineData("None", FdsMfr.UpdateNeed.None)]
+    public void UpdateNeedValue_ValidName_Parses(string name, FdsMfr.UpdateNeed expected)
+    {
+        Assert.Equal(expected, FdsMfr.UpdateNeedValue(name));
+    }
+
+    [Fact]
+    public void UpdateNeedValue_UnknownName_Throws()
+    {
+        Assert.ThrowsAny<Exception>(() => FdsMfr.UpdateNeedValue("Bogus"));
+    }
+
+    [Fact]
+    public void UpdateNeed_NumericValues_AreStable()
+    {
+        // These map to SQL updateneed codes — must not drift.
+        Assert.Equal(5, (int)FdsMfr.UpdateNeed.Reset);
+        Assert.Equal(2, (int)FdsMfr.UpdateNeed.Full);
+        Assert.Equal(1, (int)FdsMfr.UpdateNeed.Short);
+        Assert.Equal(0, (int)FdsMfr.UpdateNeed.None);
+    }
+}
+
+/// <summary>FdsShared utility helpers — pure formatting + local file I/O.</summary>
+public class FdsSharedTests
+{
+    [Theory]
+    [InlineData((byte)0)]
+    [InlineData((byte)1)]
+    [InlineData((byte)16)]
+    [InlineData((byte)32)]
+    public void RandomString_ReturnsRequestedLength_AlphanumericOnly(byte length)
+    {
+        var s = FdsShared.RandomString(length);
+        Assert.Equal(length, s.Length);
+        Assert.All(s, c => Assert.True(char.IsLetterOrDigit(c), $"unexpected char '{c}'"));
+    }
+
+    [Fact]
+    public void ToCsv_DataRow_QuotesAndEscapesStringsWhenRequested()
+    {
+        var tbl = new DataTable();
+        tbl.Columns.Add("Name", typeof(string));
+        var row = tbl.NewRow();
+        row["Name"] = "Say \"hi\"";
+        tbl.Rows.Add(row);
+
+        Assert.Equal("\"Say \"\"hi\"\"\"", row.ToCsv(quoteStrings: true, CultureInfo.InvariantCulture));
+        Assert.Equal("Say \"hi\"", row.ToCsv(quoteStrings: false, CultureInfo.InvariantCulture));
+    }
+
+    [Fact]
+    public void ToCsv_DataRow_NullAndDbNull_RenderAsEmpty()
+    {
+        var tbl = new DataTable();
+        tbl.Columns.Add("A", typeof(string));
+        tbl.Columns.Add("B", typeof(string));
+        var row = tbl.NewRow();
+        row["A"] = DBNull.Value;
+        row["B"] = "x";
+
+        Assert.Equal(";x", row.ToCsv(quoteStrings: false, CultureInfo.InvariantCulture, delimiter: ";"));
+    }
+
+    [Fact]
+    public void ToCsv_DataRow_FormatsDecimalWithSuppliedCulture()
+    {
+        var tbl = new DataTable();
+        tbl.Columns.Add("V", typeof(decimal));
+        var row = tbl.NewRow();
+        row["V"] = 1234.5m;
+        tbl.Rows.Add(row);
+
+        Assert.Equal("1234.5", row.ToCsv(quoteStrings: false, CultureInfo.InvariantCulture));
+        Assert.Equal("1234,5", row.ToCsv(quoteStrings: false, new CultureInfo("de-DE")));
+    }
+
+    [Fact]
+    public void ToCsv_DataTable_IncludesHeaderRow_WhenRequested()
+    {
+        var tbl = new DataTable();
+        tbl.Columns.Add("Konto", typeof(string));
+        tbl.Columns.Add("Betrag", typeof(decimal));
+        tbl.Rows.Add("1200", 5m);
+        tbl.Rows.Add("1400", 6m);
+
+        var csv = tbl.ToCsv(includeHeaders: true, quoteStrings: false, fieldDelimiter: ";");
+        var lines = csv.Split("\r\n");
+
+        Assert.Equal("Konto;Betrag", lines[0]);
+        Assert.Equal("1200;5", lines[1]);
+        Assert.Equal("1400;6", lines[2]);
+    }
+
+    [Fact]
+    public void ToCsv_DataTable_CanOmitHeaders()
+    {
+        var tbl = new DataTable();
+        tbl.Columns.Add("X", typeof(string));
+        tbl.Rows.Add("a");
+
+        var csv = tbl.ToCsv(includeHeaders: false, quoteStrings: false);
+        Assert.Equal("a", csv);
+    }
+
+    [Theory]
+    [InlineData("archive.zip", "archive")]
+    [InlineData("archive.tar.gz", "archive.tar")]
+    [InlineData("noext", "noext")]
+    public void NameBase_StripsFinalExtension(string fileName, string expected)
+    {
+        var fi = new FileInfo(Path.Combine(Path.GetTempPath(), fileName));
+        Assert.Equal(expected, fi.NameBase());
+    }
+
+    [Theory]
+    [InlineData("Hello, DATEV!")]
+    [InlineData("Ümläute & Straße")]
+    public void ToByteArray_Utf8_RoundTrips(string input)
+    {
+        // Default encoding is Encoding.UTF8, so the StreamWriter emits a leading BOM.
+        var bytes = input.ToByteArray();
+        var decoded = Encoding.UTF8.GetString(bytes).TrimStart('');
+        Assert.Equal(input, decoded);
+    }
+
+    [Fact]
+    public void ToByteArray_Iso8859_1_RoundTrips()
+    {
+        const string input = "Grüße";
+        var latin1 = Encoding.GetEncoding("ISO-8859-1");
+        var bytes = input.ToByteArray(latin1);
+        Assert.Equal(input, latin1.GetString(bytes));
+    }
+
+    [Fact]
+    public void ReadWriteStream_CopiesFullContent()
+    {
+        var payload = Encoding.UTF8.GetBytes("stream-copy-payload-0123456789");
+        using var src = new MemoryStream(payload);
+        using var dst = new MemoryStream();
+
+        Assert.True(FdsShared.ReadWriteStream(src, dst, closeWriteStream: false));
+        Assert.Equal(payload, dst.ToArray());
+    }
+
+    [Fact]
+    public void WriteStreamToDisk_PersistsStreamToFile()
+    {
+        var payload = Encoding.UTF8.GetBytes("disk-payload");
+        var path = Path.Combine(Path.GetTempPath(), $"fds_test_{Guid.NewGuid():N}.bin");
+        try
+        {
+            using var src = new MemoryStream(payload);
+            Assert.True(FdsShared.WriteStreamToDisk(src, path));
+            Assert.True(File.Exists(path));
+            Assert.Equal(payload, File.ReadAllBytes(path));
+        }
+        finally
+        {
+            if (File.Exists(path)) File.Delete(path);
+        }
+    }
+}
+
+/// <summary>
+/// FdsConfig + FdsMfrClient share process-global config state (FdsConfig._config),
+/// so their tests are grouped into one collection to run sequentially and never
+/// clobber each other's <see cref="FdsConfig.Initialize"/> call.
+/// </summary>
+[CollectionDefinition("FdsConfig")]
+public class FdsConfigCollection { }
+
+[Collection("FdsConfig")]
+public class FdsConfigTests
+{
+    private static IConfiguration BuildConfig(Dictionary<string, string?> values) =>
+        new ConfigurationBuilder().AddInMemoryCollection(values).Build();
+
+    [Fact]
+    public void FDSConnectionString_ReturnsConfiguredValue()
+    {
+        FdsConfig.Initialize(BuildConfig(new()
+        {
+            ["ConnectionStrings:fuchs_fds_ConnectionString"] = "Server=.;Database=fds;",
+        }));
+        Assert.Equal("Server=.;Database=fds;", FdsConfig.FDSConnectionString());
+    }
+
+    [Fact]
+    public void FDSConnectionString_Missing_Throws()
+    {
+        FdsConfig.Initialize(BuildConfig(new()));
+        Assert.Throws<InvalidOperationException>(() => FdsConfig.FDSConnectionString());
+    }
+
+    [Fact]
+    public void MfrSettings_ResolveFromFdsSection()
+    {
+        FdsConfig.Initialize(BuildConfig(new()
+        {
+            ["Fds:MFR_UserName"] = "system@example.com",
+            ["Fds:MFR_Password"] = "secret",
+            ["Fds:MFR_host"] = "portal.mobilefieldreport.com",
+        }));
+
+        Assert.Equal("system@example.com", FdsConfig.MFR_UserName);
+        Assert.Equal("secret", FdsConfig.MFR_Password);
+        Assert.Equal("portal.mobilefieldreport.com", FdsConfig.MFR_host);
+    }
+
+    [Fact]
+    public void MfrSettings_Absent_FallBackToEmptyString()
+    {
+        FdsConfig.Initialize(BuildConfig(new()));
+        Assert.Equal("", FdsConfig.MFR_UserName);
+        Assert.Equal("", FdsConfig.MFR_Password);
+        Assert.Equal("", FdsConfig.MFR_host);
+    }
+}
+
+[Collection("FdsConfig")]
+public class FdsMfrClientTests
+{
+    private static void InitConfig(string host) =>
+        FdsConfig.Initialize(new ConfigurationBuilder().AddInMemoryCollection(new Dictionary<string, string?>
+        {
+            ["Fds:MFR_host"] = host,
+            ["Fds:MFR_UserName"] = "u",
+            ["Fds:MFR_Password"] = "p",
+        }).Build());
+
+    [Fact]
+    public void Construction_BuildsClientConfig_FromHost()
+    {
+        InitConfig("portal.mobilefieldreport.com");
+        using var client = new FdsMfrClient();
+        Assert.Contains("portal.mobilefieldreport.com", client.ClientConfig.BaseUrl);
+        Assert.EndsWith("/", client.ClientConfig.BaseUrl);
+    }
+
+    [Fact]
+    public void IsReadonly_DefaultsTrue_AndIsSettable()
+    {
+        InitConfig("portal.mobilefieldreport.com");
+        using var client = new FdsMfrClient();
+        Assert.True(client.IsReadonly);
+        client.IsReadonly = false;
+        Assert.False(client.IsReadonly);
+    }
+}

Fuchs.Tests/FdsInvoiceDataBlocksTests.cs

@@ -0,0 +1,52 @@
+using System.Linq;
+using Fuchs.intranet;
+using Newtonsoft.Json.Linq;
+using Xunit;
+
+namespace Fuchs.Tests;
+
+/// <summary>
+/// Verifies the block projection that feeds the PDF item table: each service-request
+/// group exposes its heading (the section title the editor shows) and its line items,
+/// so the PDF can print a heading row per block and the flat item list still works.
+/// </summary>
+public class FdsInvoiceDataBlocksTests
+{
+    private static FdsInvoiceData FromReq(string reqJson) =>
+        new(JObject.Parse(@"{'admin':{'type':'r'},'new':{},'sms':{},'req':" + reqJson + "}"));
+
+    [Fact]
+    public void InvoiceBlocks_ExposesHeadingFromTextThenNme_AndItems()
+    {
+        var inv = FromReq(@"[
+          {'Id':'1','text':'Sektion A','items':[{'id':'a','type':'material','title':'X','price_net':10,'total_net':10}]},
+          {'Id':'2','nme':'Sektion B','items':[{'id':'b','type':'material','title':'Y','price_net':20,'total_net':20}]}
+        ]");
+
+        var blocks = inv.InvoiceBlocks;
+
+        Assert.Equal(2, blocks.Count);
+        Assert.Equal("Sektion A", blocks[0].Heading);
+        Assert.Equal("Sektion B", blocks[1].Heading);      // falls back to nme
+        Assert.Single(blocks[0].Items);
+        Assert.Equal("X", blocks[0].Items[0]["title"]);
+    }
+
+    [Fact]
+    public void InvoiceBlocks_MissingHeading_IsEmpty()
+    {
+        var inv = FromReq(@"[{'Id':'1','items':[{'id':'a','type':'material','total_net':5}]}]");
+        Assert.Equal("", Assert.Single(inv.InvoiceBlocks).Heading);
+    }
+
+    [Fact]
+    public void InvoiceItems_StillFlattensAcrossBlocks()
+    {
+        var inv = FromReq(@"[
+          {'Id':'1','text':'A','items':[{'id':'a','type':'material','total_net':10}]},
+          {'Id':'2','text':'B','items':[{'id':'b','type':'material','total_net':20},{'id':'c','type':'material','total_net':30}]}
+        ]");
+
+        Assert.Equal(new[] { "a", "b", "c" }, inv.InvoiceItems.Select(i => i["id"]!.ToString()).ToArray());
+    }
+}

Fuchs.Tests/Fuchs.Tests.csproj

@@ -9,8 +9,8 @@
   </PropertyGroup>
 
   <ItemGroup>
-    <PackageReference Include="Microsoft.NET.Test.Sdk" Version="18.7.0" />
-    <PackageReference Include="xunit" Version="2.9.3" />
+    <PackageReference Include="Microsoft.NET.Test.Sdk" Version="18.8.1" />
+    <PackageReference Include="xunit.v3" Version="3.2.2" />
     <PackageReference Include="xunit.runner.visualstudio" Version="3.1.5">
       <IncludeAssets>runtime; build; native; contentfiles; analyzers; buildtransitive</IncludeAssets>
       <PrivateAssets>all</PrivateAssets>
@@ -28,6 +28,7 @@
     <ProjectReference Include="..\MFR_RESTClient\MFR_RESTClient.csproj" />
     <ProjectReference Include="..\..\..\WebProjectComponents\MT940Parser\MT940Parser\MT940Parser.csproj" />
     <ProjectReference Include="..\CAMTParser\CAMTParser.csproj" />
+    <ProjectReference Include="..\eRechnungLib\src\eRechnungLib\eRechnungLib.csproj" />
   </ItemGroup>
 
   <ItemGroup>

Fuchs.Tests/InvoiceDraftCacheTests.cs

@@ -0,0 +1,113 @@
+using System;
+using System.Collections.Generic;
+using System.Threading;
+using System.Threading.Tasks;
+using Fuchs.intranet;
+using Fuchs.Notifications;
+using Fuchs.Services;
+using Microsoft.Extensions.Configuration;
+using Microsoft.Extensions.Logging.Abstractions;
+using Xunit;
+
+namespace Fuchs.Tests;
+
+/// <summary>
+/// Covers the in-memory draft cache (storage + idle sliding TTL) and the background
+/// expiry monitor that warns before eviction and closes the editor on eviction (ADR 0006).
+/// </summary>
+public class InvoiceDraftCacheTests
+{
+    private static IConfiguration Config(int idle = 30, int warn = 5) =>
+        new ConfigurationBuilder().AddInMemoryCollection(new Dictionary<string, string?>
+        {
+            ["Fuchs:DraftEditing:IdleMinutes"] = idle.ToString(),
+            ["Fuchs:DraftEditing:ExpiryWarnMinutes"] = warn.ToString()
+        }).Build();
+
+    private sealed class FakeNotifier : IDraftNotifier
+    {
+        public readonly List<(string token, int version)> Ready = new();
+        public readonly List<(string token, int secondsLeft)> Expiring = new();
+        public readonly List<(string token, string reason)> Closed = new();
+        public Task SignalDraftReadyAsync(string token, int version, CancellationToken ct = default) { Ready.Add((token, version)); return Task.CompletedTask; }
+        public Task SignalExpiringAsync(string token, int secondsLeft, CancellationToken ct = default) { Expiring.Add((token, secondsLeft)); return Task.CompletedTask; }
+        public Task SignalClosedAsync(string token, string reason, CancellationToken ct = default) { Closed.Add((token, reason)); return Task.CompletedTask; }
+    }
+
+    // ── Cache storage ─────────────────────────────────────────────────────────
+    [Fact]
+    public void SetGet_RoundTrips_AndUnknownTokenIsNull()
+    {
+        var cache = new InvoiceDraftCache(Config());
+        var s = new InvoiceDraftSession { Token = "abc" };
+        cache.Set(s);
+        Assert.Same(s, cache.Get("abc"));
+        Assert.Null(cache.Get("nope"));
+    }
+
+    [Fact]
+    public void Remove_EvictsSession()
+    {
+        var cache = new InvoiceDraftCache(Config());
+        cache.Set(new InvoiceDraftSession { Token = "x" });
+        Assert.NotNull(cache.Remove("x"));
+        Assert.Null(cache.Get("x"));
+        Assert.Null(cache.Remove("x"));
+    }
+
+    [Fact]
+    public void Get_ResetsExpiryWarningFlag_SoAFreshWarningIsDue()
+    {
+        var cache = new InvoiceDraftCache(Config());
+        var s = new InvoiceDraftSession { Token = "x", ExpiryWarningSent = true };
+        cache.Set(s);
+        cache.Get("x");
+        Assert.False(s.ExpiryWarningSent);
+    }
+
+    // ── Expiry monitor ────────────────────────────────────────────────────────
+    [Fact]
+    public async Task Sweep_NearTtl_WarnsOnceThenEvictsWithReason()
+    {
+        var cfg = Config(idle: 30, warn: 5);
+        var cache = new InvoiceDraftCache(cfg);
+        var notifier = new FakeNotifier();
+        var svc = new InvoiceDraftExpiryService(cache, notifier, cfg, NullLogger<InvoiceDraftExpiryService>.Instance);
+
+        var s = new InvoiceDraftSession { Token = "a" };
+        cache.Set(s);
+
+        // Idle 26 min → inside the 5-min warning window (30-5=25) but not yet expired.
+        s.LastAccessUtc = DateTime.UtcNow.AddMinutes(-26);
+        await svc.SweepAsync(CancellationToken.None);
+        Assert.Single(notifier.Expiring);
+        Assert.Empty(notifier.Closed);
+        Assert.True(s.ExpiryWarningSent);
+
+        // Another sweep while still idle must not spam a second warning.
+        await svc.SweepAsync(CancellationToken.None);
+        Assert.Single(notifier.Expiring);
+
+        // Past the TTL → evicted and the editor is told to close with a reason.
+        s.LastAccessUtc = DateTime.UtcNow.AddMinutes(-31);
+        await svc.SweepAsync(CancellationToken.None);
+        Assert.Single(notifier.Closed);
+        Assert.Equal(("a", "expired"), notifier.Closed[0]);
+        Assert.Null(cache.Get("a"));
+    }
+
+    [Fact]
+    public async Task Sweep_FreshSession_DoesNothing()
+    {
+        var cfg = Config(idle: 30, warn: 5);
+        var cache = new InvoiceDraftCache(cfg);
+        var notifier = new FakeNotifier();
+        var svc = new InvoiceDraftExpiryService(cache, notifier, cfg, NullLogger<InvoiceDraftExpiryService>.Instance);
+        cache.Set(new InvoiceDraftSession { Token = "fresh" });
+
+        await svc.SweepAsync(CancellationToken.None);
+
+        Assert.Empty(notifier.Expiring);
+        Assert.Empty(notifier.Closed);
+    }
+}

Fuchs.Tests/InvoiceDraftCalculatorTests.cs

@@ -0,0 +1,294 @@
+using Fuchs.intranet;
+using Newtonsoft.Json.Linq;
+using Xunit;
+
+namespace Fuchs.Tests;
+
+/// <summary>
+/// Verifies the server-side aggregation of invoice draft totals (the port of the
+/// former client-side <c>invSumUpdate</c> footer math). The truth now lives in the
+/// backend (ADR 0006), so this is unit-testable directly. Line values are read from
+/// each block's <c>itm</c> array (the editor's <c>co</c> objects: <c>vt</c>=net,
+/// <c>vv</c>=VAT, <c>vs</c>=service-net, <c>vsv</c>=service-VAT, <c>vat</c>=rate).
+/// </summary>
+public class InvoiceDraftCalculatorTests
+{
+    private static InvoiceDraftSession SessionWith(string reqJson, bool p13b = false)
+    {
+        var s = new InvoiceDraftSession { Token = "t" };
+        s.Admin = new JObject { ["p13b"] = p13b };
+        s.New = new JObject { ["invoiceemail"] = "kunde@example.de", ["invoiceaddress"] = "Weg 1" };
+        s.Req = JArray.Parse(reqJson);
+        return s;
+    }
+
+    // ── RecomputeLineValues ────────────────────────────────────────────────────
+    private static JObject Line(InvoiceDraftSession s, int block, int line) =>
+        (JObject)((JArray)((JObject)s.Req[block])["itm"]!)[line];
+
+    [Fact]
+    public void RecomputeLineValues_ComputesNetAndVatFromRawQtyPriceAndRate()
+    {
+        var s = SessionWith(@"[
+          { 'Id':'10','itm':[ {'id':'a','typ':'material','qn':2,'v':50,'vat':'19%'} ] }
+        ]");
+
+        InvoiceDraftCalculator.RecomputeLineValues(s);
+
+        var l = Line(s, 0, 0);
+        Assert.Equal(100m, l["vt"]!.Value<decimal>());
+        Assert.Equal(19m, l["vv"]!.Value<decimal>());
+        Assert.Equal(0m, l["vs"]!.Value<decimal>());
+        Assert.Equal(0m, l["vsv"]!.Value<decimal>());
+    }
+
+    [Fact]
+    public void RecomputeLineValues_ServiceType_AlsoFillsServiceNetAndVat()
+    {
+        var s = SessionWith(@"[
+          { 'Id':'10','itm':[ {'id':'a','typ':'Service','qn':3,'v':10,'vat':'19%'} ] }
+        ]");
+
+        InvoiceDraftCalculator.RecomputeLineValues(s);
+
+        var l = Line(s, 0, 0);
+        Assert.Equal(30m, l["vt"]!.Value<decimal>());
+        Assert.Equal(5.7m, l["vv"]!.Value<decimal>());
+        Assert.Equal(30m, l["vs"]!.Value<decimal>());
+        Assert.Equal(5.7m, l["vsv"]!.Value<decimal>());
+    }
+
+    [Theory]
+    [InlineData(0, 50)]     // no quantity posted -> leave value untouched
+    [InlineData(2, 0)]      // no price posted -> leave value untouched
+    public void RecomputeLineValues_MissingQtyOrPrice_LeavesExistingValueUntouched(decimal qty, decimal price)
+    {
+        var s = SessionWith($@"[
+          {{ 'Id':'10','itm':[ {{'id':'a','typ':'material','qn':{qty},'v':{price},'vat':'19%','vt':777,'vv':111}} ] }}
+        ]");
+
+        InvoiceDraftCalculator.RecomputeLineValues(s);
+
+        var l = Line(s, 0, 0);
+        Assert.Equal(777m, l["vt"]!.Value<decimal>());   // untouched — mirrors quantChange's own guard
+        Assert.Equal(111m, l["vv"]!.Value<decimal>());
+    }
+
+    [Fact]
+    public void RecomputeLineValues_ZeroVatRate_ComputesNetWithNoVat()
+    {
+        var s = SessionWith(@"[
+          { 'Id':'10','itm':[ {'id':'a','typ':'material','qn':4,'v':25,'vat':'0%'} ] }
+        ]");
+
+        InvoiceDraftCalculator.RecomputeLineValues(s);
+
+        var l = Line(s, 0, 0);
+        Assert.Equal(100m, l["vt"]!.Value<decimal>());
+        Assert.Equal(0m, l["vv"]!.Value<decimal>());
+    }
+
+    [Fact]
+    public void RecomputeLineValues_SetHeaderConvertedSum_IsNotClobberedByRecompute()
+    {
+        // A converted set header carries a synthesised sum (no raw qty/price of its own) —
+        // RecomputeLineValues must never overwrite it, mirroring quantChange's guard.
+        var s = SessionWith(@"[
+          { 'Id':'10','itm':[ {'id':'h','typ':'set','vt':1000,'vv':190,'vat':'19%'} ] }
+        ]");
+
+        InvoiceDraftCalculator.RecomputeLineValues(s);
+
+        var l = Line(s, 0, 0);
+        Assert.Equal(1000m, l["vt"]!.Value<decimal>());
+        Assert.Equal(190m, l["vv"]!.Value<decimal>());
+    }
+
+    [Fact]
+    public void RecomputeTotals_SumsNetVatServiceAndPerBlock()
+    {
+        var s = SessionWith(@"[
+          { 'Id':'10','itm':[
+             {'vt':100,'vv':19,'vs':0,'vsv':0,'vat':'19%'},
+             {'vt':50,'vv':9.5,'vs':50,'vsv':9.5,'vat':'19%'} ] },
+          { 'Id':'11','itm':[
+             {'vt':200,'vv':14,'vs':0,'vsv':0,'vat':'7%'} ] }
+        ]");
+
+        InvoiceDraftCalculator.RecomputeTotals(s);
+
+        Assert.Equal(350m, s.Sums.TotalNet);
+        Assert.Equal(42.5m, s.Sums.TotalVat);
+        Assert.Equal(392.5m, s.Sums.TotalGross);
+        Assert.Equal(50m, s.Sums.ServiceNet);
+        Assert.Equal(9.5m, s.Sums.ServiceVat);
+        Assert.Equal(28.5m, s.Sums.VatByRate["19"]);
+        Assert.Equal(14m, s.Sums.VatByRate["7"]);
+        Assert.Equal(150m, s.Sums.NetByBlock["10"]);
+        Assert.Equal(200m, s.Sums.NetByBlock["11"]);
+    }
+
+    [Fact]
+    public void RecomputeTotals_ReverseCharge_SuppressesVatAndGrossEqualsNet()
+    {
+        var s = SessionWith(@"[{ 'Id':'1','itm':[ {'vt':100,'vv':19,'vat':'19%'} ] }]", p13b: true);
+
+        InvoiceDraftCalculator.RecomputeTotals(s);
+
+        Assert.Equal(100m, s.Sums.TotalNet);
+        Assert.Equal(100m, s.Sums.TotalGross);
+        Assert.Equal(0m, s.Sums.TotalVat);
+        Assert.Empty(s.Sums.VatByRate);
+    }
+
+    [Fact]
+    public void RecomputeTotals_EmptyDraft_AllZero()
+    {
+        var s = SessionWith("[]");
+        InvoiceDraftCalculator.RecomputeTotals(s);
+        Assert.Equal(0m, s.Sums.TotalNet);
+        Assert.Equal(0m, s.Sums.TotalGross);
+        Assert.Empty(s.Sums.VatByRate);
+    }
+
+    [Theory]
+    [InlineData("19,0%", "19")]
+    [InlineData("7%", "7")]
+    [InlineData("19", "19")]
+    [InlineData("", "")]
+    [InlineData("0", "")]
+    [InlineData("7,5", "7.5")]
+    public void NormalizeRate_CanonicalisesRateStrings(string raw, string expected)
+        => Assert.Equal(expected, InvoiceDraftCalculator.NormalizeRate(raw));
+
+    [Fact]
+    public void Validate_ValidDraft_NoErrors()
+    {
+        var s = SessionWith(@"[{ 'Id':'1','itm':[ {'vt':100,'vv':19,'vat':'19%'} ] }]");
+        InvoiceDraftCalculator.RecomputeTotals(s);
+        InvoiceDraftCalculator.Validate(s);
+        Assert.DoesNotContain(s.ValidationMessages, m => m.Severity == "error");
+    }
+
+    [Theory]
+    [InlineData("", "warning")]
+    [InlineData("not-an-email", "error")]
+    public void Validate_EmailProblems_AreFlagged(string email, string severity)
+    {
+        var s = SessionWith(@"[{ 'Id':'1','itm':[{'vt':10,'vat':'19%'}] }]");
+        s.New["invoiceemail"] = email;
+        InvoiceDraftCalculator.RecomputeTotals(s);
+        InvoiceDraftCalculator.Validate(s);
+        Assert.Contains(s.ValidationMessages, m => m.Field == "email" && m.Severity == severity);
+    }
+
+    [Fact]
+    public void Validate_NoItems_IsError()
+    {
+        var s = SessionWith("[]");
+        InvoiceDraftCalculator.RecomputeTotals(s);
+        InvoiceDraftCalculator.Validate(s);
+        Assert.Contains(s.ValidationMessages, m => m.Field == "items" && m.Severity == "error");
+    }
+
+    [Fact]
+    public void Validate_UnknownVatRate_IsWarning()
+    {
+        var s = SessionWith(@"[{ 'Id':'1','itm':[{'vt':10,'vv':0.5,'vat':'5%'}] }]");
+        InvoiceDraftCalculator.RecomputeTotals(s);
+        InvoiceDraftCalculator.Validate(s);
+        Assert.Contains(s.ValidationMessages, m => m.Field == "vat" && m.Severity == "warning");
+    }
+
+    [Fact]
+    public void Validate_MissingAddress_IsWarning()
+    {
+        var s = SessionWith(@"[{ 'Id':'1','itm':[{'vt':10,'vat':'19%'}] }]");
+        s.New["invoiceaddress"] = "";
+        InvoiceDraftCalculator.RecomputeTotals(s);
+        InvoiceDraftCalculator.Validate(s);
+        Assert.Contains(s.ValidationMessages, m => m.Field == "address" && m.Severity == "warning");
+    }
+
+    [Fact]
+    public void Validate_NegativeTotal_IsWarning()
+    {
+        var s = SessionWith(@"[{ 'Id':'1','itm':[{'vt':-50,'vv':0,'vat':''}] }]");
+        InvoiceDraftCalculator.RecomputeTotals(s);
+        InvoiceDraftCalculator.Validate(s);
+        Assert.Contains(s.ValidationMessages, m => m.Field == "total" && m.Severity == "warning");
+    }
+
+    // ── RecomputePositions ────────────────────────────────────────────────────
+    private static string Pos(InvoiceDraftSession s, int block, int line) =>
+        ((JObject)((JArray)((JObject)s.Req[block])["itm"]!)[line])["p"]!.ToString();
+
+    [Fact]
+    public void RecomputePositions_NumbersPricedLinesContinuouslyAcrossBlocks()
+    {
+        var s = SessionWith(@"[
+          { 'Id':'10','itm':[ {'id':'a','typ':'material','vt':1}, {'id':'b','typ':'service','vt':2} ] },
+          { 'Id':'11','itm':[ {'id':'c','typ':'material','vt':3} ] }
+        ]");
+
+        InvoiceDraftCalculator.RecomputePositions(s);
+
+        Assert.Equal("1", Pos(s, 0, 0));
+        Assert.Equal("2", Pos(s, 0, 1));
+        Assert.Equal("3", Pos(s, 1, 0));   // continuous, not restarting per block
+    }
+
+    [Fact]
+    public void RecomputePositions_SkipsHeadingAndFreeTextLines()
+    {
+        var s = SessionWith(@"[
+          { 'Id':'10','itm':[
+             {'id':'t','typ':'Title','vt':0},
+             {'id':'a','typ':'material','vt':1},
+             {'id':'x','typ':'Text','vt':0},
+             {'id':'b','typ':'material','vt':2} ] }
+        ]");
+
+        InvoiceDraftCalculator.RecomputePositions(s);
+
+        Assert.Equal("", Pos(s, 0, 0));    // title carries no number
+        Assert.Equal("1", Pos(s, 0, 1));
+        Assert.Equal("", Pos(s, 0, 2));    // free text carries no number
+        Assert.Equal("2", Pos(s, 0, 3));
+    }
+
+    [Fact]
+    public void RecomputePositions_NumbersSetHeaderLikeAnyItem()
+    {
+        // A set header is numbered just like the editor numbers it — only text/title lines are skipped.
+        var s = SessionWith(@"[
+          { 'Id':'10','itm':[
+             {'id':'h','typ':'set','vt':1000},
+             {'id':'a','typ':'material','vt':600},
+             {'id':'b','typ':'material','vt':400} ] }
+        ]");
+
+        InvoiceDraftCalculator.RecomputePositions(s);
+
+        Assert.Equal("1", Pos(s, 0, 0));   // set header keeps position 1 (matches the editor)
+        Assert.Equal("2", Pos(s, 0, 1));
+        Assert.Equal("3", Pos(s, 0, 2));
+    }
+
+    [Fact]
+    public void RecomputePositions_AfterBlockOrderChange_RenumbersToNewSequence()
+    {
+        var s = SessionWith(@"[
+          { 'Id':'10','itm':[ {'id':'a','typ':'material','vt':1} ] },
+          { 'Id':'11','itm':[ {'id':'b','typ':'material','vt':2} ] }
+        ]");
+        // Simulate a section reorder: swap the two blocks.
+        var b0 = s.Req[0]; var b1 = s.Req[1];
+        s.Req = new JArray(b1.DeepClone(), b0.DeepClone());
+
+        InvoiceDraftCalculator.RecomputePositions(s);
+
+        Assert.Equal("1", Pos(s, 0, 0));   // formerly block 11's item is now position 1
+        Assert.Equal("2", Pos(s, 1, 0));
+    }
+}

Fuchs.Tests/InvoiceDraftNotifierTests.cs

@@ -0,0 +1,126 @@
+using System;
+using System.Collections.Generic;
+using System.Threading;
+using System.Threading.Tasks;
+using Fuchs.Notifications;
+using Microsoft.AspNetCore.SignalR;
+using Microsoft.Extensions.Logging.Abstractions;
+using Newtonsoft.Json.Linq;
+using Xunit;
+
+namespace Fuchs.Tests;
+
+/// <summary>
+/// Verifies <see cref="DraftNotifier"/> targets the draft's SignalR group (keyed by
+/// session token, ADR 0007) with the right method/payload, and — like the other
+/// notification path — swallows hub failures so a missed coordination ping never
+/// fails the underlying operation.
+/// </summary>
+public class InvoiceDraftNotifierTests
+{
+    private sealed class CapturingClientProxy : IClientProxy
+    {
+        private readonly bool _throw;
+        public string? Method { get; private set; }
+        public object?[]? Args { get; private set; }
+        public CapturingClientProxy(bool doThrow = false) => _throw = doThrow;
+        public Task SendCoreAsync(string method, object?[] args, CancellationToken cancellationToken = default)
+        {
+            if (_throw) throw new InvalidOperationException("hub down");
+            Method = method;
+            Args = args;
+            return Task.CompletedTask;
+        }
+    }
+
+    private sealed class StubHubClients : IHubClients
+    {
+        private readonly IClientProxy _proxy;
+        public string? RequestedGroup { get; private set; }
+        public StubHubClients(IClientProxy proxy) => _proxy = proxy;
+        public IClientProxy Group(string groupName) { RequestedGroup = groupName; return _proxy; }
+        public IClientProxy All => throw new NotImplementedException();
+        public IClientProxy AllExcept(IReadOnlyList<string> e) => throw new NotImplementedException();
+        public IClientProxy Client(string c) => throw new NotImplementedException();
+        public IClientProxy Clients(IReadOnlyList<string> c) => throw new NotImplementedException();
+        public IClientProxy Groups(IReadOnlyList<string> g) => throw new NotImplementedException();
+        public IClientProxy GroupExcept(string g, IReadOnlyList<string> e) => throw new NotImplementedException();
+        public IClientProxy User(string u) => throw new NotImplementedException();
+        public IClientProxy Users(IReadOnlyList<string> u) => throw new NotImplementedException();
+    }
+
+    private sealed class StubHubContext : IHubContext<DraftPreviewHub>
+    {
+        public StubHubContext(IHubClients clients) => Clients = clients;
+        public IHubClients Clients { get; }
+        public IGroupManager Groups => throw new NotImplementedException();
+    }
+
+    private static (DraftNotifier notifier, StubHubClients clients, CapturingClientProxy proxy) Create(bool doThrow = false)
+    {
+        var proxy = new CapturingClientProxy(doThrow);
+        var clients = new StubHubClients(proxy);
+        var notifier = new DraftNotifier(new StubHubContext(clients), NullLogger<DraftNotifier>.Instance);
+        return (notifier, clients, proxy);
+    }
+
+    [Fact]
+    public async Task SignalDraftReadyAsync_SendsToTokenGroupWithVersion()
+    {
+        var (notifier, clients, proxy) = Create();
+
+        await notifier.SignalDraftReadyAsync("tok-1", 7);
+
+        Assert.Equal("tok-1", clients.RequestedGroup);
+        Assert.Equal("draftReady", proxy.Method);
+        var payload = JObject.FromObject(proxy.Args![0]!);
+        Assert.Equal("tok-1", payload["token"]!.Value<string>());
+        Assert.Equal(7, payload["version"]!.Value<int>());
+    }
+
+    [Fact]
+    public async Task SignalExpiringAsync_SendsSecondsLeft()
+    {
+        var (notifier, _, proxy) = Create();
+
+        await notifier.SignalExpiringAsync("tok-2", 120);
+
+        Assert.Equal("draftExpiring", proxy.Method);
+        var payload = JObject.FromObject(proxy.Args![0]!);
+        Assert.Equal(120, payload["secondsLeft"]!.Value<int>());
+    }
+
+    [Fact]
+    public async Task SignalClosedAsync_SendsReason()
+    {
+        var (notifier, _, proxy) = Create();
+
+        await notifier.SignalClosedAsync("tok-3", "expired");
+
+        Assert.Equal("draftClosed", proxy.Method);
+        var payload = JObject.FromObject(proxy.Args![0]!);
+        Assert.Equal("expired", payload["reason"]!.Value<string>());
+    }
+
+    [Fact]
+    public async Task EmptyToken_DoesNotSend()
+    {
+        var (notifier, clients, proxy) = Create();
+
+        await notifier.SignalDraftReadyAsync("", 1);
+
+        Assert.Null(clients.RequestedGroup);
+        Assert.Null(proxy.Method);
+    }
+
+    [Fact]
+    public async Task HubFailure_IsSwallowed()
+    {
+        var (notifier, _, _) = Create(doThrow: true);
+
+        // Must not throw — a failed coordination ping cannot fail the caller's operation.
+        await notifier.SignalDraftReadyAsync("tok", 1);
+        await notifier.SignalExpiringAsync("tok", 60);
+        await notifier.SignalClosedAsync("tok", "expired");
+    }
+}

Fuchs.Tests/InvoiceDraftServiceTests.cs

@@ -0,0 +1,873 @@
+using System.Linq;
+using System.Threading.Tasks;
+using Fuchs.intranet;
+using Fuchs.Services;
+using Microsoft.Extensions.Configuration;
+using Microsoft.Extensions.Logging.Abstractions;
+using MigraDoc.DocumentObjectModel;
+using Newtonsoft.Json.Linq;
+using OCORE.security;
+using Xunit;
+using static OCORE.OCORE_dictionaries;
+
+namespace Fuchs.Tests;
+
+/// <summary>
+/// Exercises the draft edit orchestrator's pure paths (open/patch/history/flush)
+/// without a database, proving the backend-authoritative model behaves correctly at
+/// the service seam (ADR 0006). Blocks use the editor's <c>itm</c>/<c>items</c> shape.
+/// </summary>
+public class InvoiceDraftServiceTests
+{
+    /// <summary>Captures the invoice handed to registration and returns it with a fake DB id — no SQL.</summary>
+    private sealed class FakeInvoiceService : IInvoiceService
+    {
+        public FdsInvoiceData? Registered;
+        public bool? LastChange;
+        public Task<FdsInvoiceData> RegisterInvoiceAsync(FdsInvoiceData invoice, bool change, string invId, string userAccountId, DatabaseSecurity dbSec)
+        {
+            Registered = invoice;
+            LastChange = change;
+            invoice.InvoiceRegistration = new GenericObjectDictionary(new System.Collections.Generic.Dictionary<string, object> { ["Id"] = "INV42" });
+            return Task.FromResult(invoice);
+        }
+        public FdsInvoiceData? PreviewInvoice;
+        public bool? PreviewDraft;
+        public Task<FdsInvoiceData> LoadInvoiceAsync(string id, string u, DatabaseSecurity s) => throw new System.NotSupportedException();
+        public Document GenerateInvoicePdf(FdsInvoiceData i, bool d) { PreviewInvoice = i; PreviewDraft = d; return new Document(); }
+        public Task<byte[]> RenderInvoicePdfBytesAsync(FdsInvoiceData i, bool d) => throw new System.NotSupportedException();
+        public Task<byte[]> StoreInvoiceDocumentFileAsync(FdsInvoiceData i, bool d, string u, DatabaseSecurity s) => throw new System.NotSupportedException();
+        public Task<byte[]?> GetInvoiceFileAsync(FdsInvoiceData i, bool d, fds.IFdsMfr m) => throw new System.NotSupportedException();
+    }
+
+    private static (InvoiceDraftEditService svc, FakeInvoiceService inv, InvoiceDraftCache cache) NewService()
+    {
+        var cache = new InvoiceDraftCache(new ConfigurationBuilder().Build());
+        var inv = new FakeInvoiceService();
+        var svc = new InvoiceDraftEditService(cache, inv, NullLogger<InvoiceDraftEditService>.Instance);
+        return (svc, inv, cache);
+    }
+
+    private static JObject Payload() => JObject.Parse(@"{
+        'admin':{'p13b':false,'type':'r','paymentterms':'10wd'},
+        'new':{'invoiceemail':'a@b.de','invoiceaddress':'Weg 1','invoicetitle':'Rechnung'},
+        'req':[{'Id':'1','text':'Auftrag','itm':[{'id':'900','typ':'material','vt':100,'vv':19,'vs':0,'vsv':0,'vat':'19%'}],
+                'items':[{'id':'900','type':'material','total_net':100,'vat':'19%'}]}]
+    }");
+
+    [Fact]
+    public void OpenFromPayload_SeedsSessionAndComputesTotals()
+    {
+        var (svc, _, _) = NewService();
+        var s = svc.OpenFromPayload(Payload(), "user1");
+        Assert.False(string.IsNullOrEmpty(s.Token));
+        Assert.Equal(0, s.Version);
+        Assert.Equal(100m, s.Sums.TotalNet);
+        Assert.Equal(119m, s.Sums.TotalGross);
+    }
+
+    [Fact]
+    public void ApplyPatch_Email_MutatesBumpsVersionAndRecordsHistory()
+    {
+        var (svc, _, _) = NewService();
+        var s = svc.OpenFromPayload(Payload(), "user1");
+
+        var s2 = svc.ApplyPatch(s.Token, new InvoiceDraftDelta { Target = "email", Value = JToken.FromObject("neu@x.de") });
+
+        Assert.NotNull(s2);
+        Assert.Equal(1, s2!.Version);
+        Assert.Equal("neu@x.de", s2.New["invoiceemail"]!.Value<string>());
+        var h = Assert.Single(s2.History);
+        Assert.Equal("email", h.Target);
+        Assert.Equal("a@b.de", h.OldValue);
+        Assert.Equal("neu@x.de", h.NewValue);
+        Assert.Equal(1, h.Version);
+    }
+
+    [Fact]
+    public void ApplyPatch_StructuredAddress_ComposesFreeTextAndPersistsJson()
+    {
+        var (svc, _, _) = NewService();
+        var s = svc.OpenFromPayload(Payload(), "user1");
+
+        var addr = JObject.Parse(@"{'name':'Muster GmbH','street':'Weg 1','postalCode':'40223','city':'Düsseldorf','countryCode':'DE','vatId':'DE123456789'}");
+        var s2 = svc.ApplyPatch(s.Token, new InvoiceDraftDelta { Target = "address", Value = addr });
+
+        Assert.NotNull(s2);
+        // Free-text block is composed for the PDF / SendToAddress path.
+        Assert.Equal("Muster GmbH\nWeg 1\n40223 Düsseldorf", s2!.New["invoiceaddress"]!.Value<string>());
+        // Structured JSON rides inside the CustomValues blob (interim persistence).
+        var parsed = InvoiceRecipientAddress.FromCustomValues(s2.New["CustomValues"]!.Value<string>());
+        Assert.NotNull(parsed);
+        Assert.Equal("DE123456789", parsed!.VatId);
+        Assert.True(parsed.IsEn16931Conformant);
+    }
+
+    [Fact]
+    public void ApplyPatch_Address_PlainString_KeepsLegacyFreeTextBehavior()
+    {
+        var (svc, _, _) = NewService();
+        var s = svc.OpenFromPayload(Payload(), "user1");
+
+        var s2 = svc.ApplyPatch(s.Token, new InvoiceDraftDelta { Target = "address", Value = JToken.FromObject("Weg 9\n50667 Köln") });
+
+        Assert.Equal("Weg 9\n50667 Köln", s2!.New["invoiceaddress"]!.Value<string>());
+        Assert.Null(InvoiceRecipientAddress.FromCustomValues(s2.New["CustomValues"]?.Value<string>()));
+    }
+
+    [Fact]
+    public void ApplyPatch_BlockReplace_RecomputesTotals()
+    {
+        var (svc, _, _) = NewService();
+        var s = svc.OpenFromPayload(Payload(), "user1");
+
+        var newBlock = JObject.Parse(@"{'Id':'1','text':'Auftrag','itm':[{'id':'900','typ':'material','vt':50,'vv':9.5,'vat':'19%'}],
+                                        'items':[{'id':'900','type':'material','total_net':50,'vat':'19%'}]}");
+        var s2 = svc.ApplyPatch(s.Token, new InvoiceDraftDelta { Target = "block.replace", Ref = "1", Value = newBlock });
+
+        Assert.Equal(50m, s2!.Sums.TotalNet);
+        Assert.Equal(9.5m, s2.Sums.VatByRate["19"]);
+    }
+
+    [Fact]
+    public void ApplyPatch_BlockRemove_EmptiesDraftAndFlagsNoItems()
+    {
+        var (svc, _, _) = NewService();
+        var s = svc.OpenFromPayload(Payload(), "user1");
+
+        var s2 = svc.ApplyPatch(s.Token, new InvoiceDraftDelta { Target = "block.remove", Ref = "1" });
+
+        Assert.Equal(0m, s2!.Sums.TotalNet);
+        Assert.Contains(s2.ValidationMessages, m => m.Field == "items" && m.Severity == "error");
+    }
+
+    [Fact]
+    public void ApplyPatch_P13bToggle_FlipsAndSuppressesVat()
+    {
+        var (svc, _, _) = NewService();
+        var s = svc.OpenFromPayload(Payload(), "user1");
+
+        var s2 = svc.ApplyPatch(s.Token, new InvoiceDraftDelta { Target = "p13b" }); // no value → toggle
+
+        Assert.Equal(100m, s2!.Sums.TotalGross); // reverse-charge → gross == net
+        Assert.Empty(s2.Sums.VatByRate);
+    }
+
+    [Fact]
+    public void ApplyPatch_UnknownToken_ReturnsNull()
+    {
+        var (svc, _, _) = NewService();
+        Assert.Null(svc.ApplyPatch("ghost", new InvoiceDraftDelta { Target = "email", Value = JToken.FromObject("x@y.de") }));
+    }
+
+    [Fact]
+    public async Task FlushToDbAsync_RegistersWithMappedTotals_AndSetsInvId()
+    {
+        var (svc, inv, _) = NewService();
+        var s = svc.OpenFromPayload(Payload(), "user1");
+
+        var result = await svc.FlushToDbAsync(s.Token, "user1", null!);
+
+        Assert.NotNull(result);
+        Assert.Equal("INV42", result!.Id);
+        Assert.False(inv.LastChange);   // new draft (no prior InvId) → create, not update
+        Assert.Equal("INV42", svc.Get(s.Token)!.InvId);
+
+        var prms = inv.Registered!.BuildInvoiceParams(change: false, invId: "");
+        var balance = prms.First(p => p.ParameterName == "@InvoiceBalance");
+        Assert.Equal("119", System.Convert.ToString(balance.Value, System.Globalization.CultureInfo.InvariantCulture));
+        var vatRate = prms.First(p => p.ParameterName == "@InvoiceVAT_1");
+        Assert.Equal("19", vatRate.Value);
+    }
+
+    [Fact]
+    public void GetHistory_UnknownToken_IsEmpty()
+    {
+        var (svc, _, _) = NewService();
+        Assert.Empty(svc.GetHistory("ghost"));
+    }
+
+    [Theory]
+    [InlineData("address", "invoiceaddress")]
+    [InlineData("title", "invoicetitle")]
+    [InlineData("provisionperiod", "provisionperiod")]
+    public void ApplyPatch_ScalarFieldDeltas_UpdateNew(string target, string newKey)
+    {
+        var (svc, _, _) = NewService();
+        var s = svc.OpenFromPayload(Payload(), "user1");
+
+        var s2 = svc.ApplyPatch(s.Token, new InvoiceDraftDelta { Target = target, Value = JToken.FromObject("X-VALUE") });
+
+        Assert.Equal("X-VALUE", s2!.New[newKey]!.Value<string>());
+    }
+
+    [Fact]
+    public void ApplyPatch_ProvisionLocation_MirrorsLocAndProvisionlocation()
+    {
+        var (svc, _, _) = NewService();
+        var s = svc.OpenFromPayload(Payload(), "user1");
+
+        var s2 = svc.ApplyPatch(s.Token, new InvoiceDraftDelta { Target = "provisionlocation", Value = JToken.FromObject("Baustelle 7") });
+
+        Assert.Equal("Baustelle 7", s2!.New["provisionlocation"]!.Value<string>());
+        Assert.Equal("Baustelle 7", s2.New["loc"]!.Value<string>());
+    }
+
+    [Fact]
+    public void ApplyPatch_Contact_BuildsCustomValuesJson()
+    {
+        var (svc, _, _) = NewService();
+        var s = svc.OpenFromPayload(Payload(), "user1");
+
+        var s2 = svc.ApplyPatch(s.Token, new InvoiceDraftDelta
+        {
+            Target = "contact",
+            Value = JObject.Parse(@"{'name':'Max Mustermann','email':'max@kunde.de'}")
+        });
+
+        var cv = JObject.Parse(s2!.New["CustomValues"]!.Value<string>()!);
+        Assert.Equal("Max Mustermann", cv["contactName"]!.Value<string>());
+        Assert.Equal("max@kunde.de", cv["contactEmail"]!.Value<string>());
+    }
+
+    [Fact]
+    public void ApplyPatch_SetmodeDelta_UpdatesAdmin()
+    {
+        var (svc, _, _) = NewService();
+        var s = svc.OpenFromPayload(Payload(), "user1");
+
+        var s2 = svc.ApplyPatch(s.Token, new InvoiceDraftDelta { Target = "setmode", Value = JToken.FromObject("setonly") });
+
+        Assert.Equal("setonly", s2!.Admin["setmode"]!.Value<string>());
+    }
+
+    [Fact]
+    public void ApplyPatch_P13bExplicitFalse_TurnsOffAndRestoresVat()
+    {
+        var (svc, _, _) = NewService();
+        var payload = Payload();
+        payload["admin"]!["p13b"] = true;                    // start reverse-charge
+        var s = svc.OpenFromPayload(payload, "user1");
+        Assert.Empty(s.Sums.VatByRate);
+
+        var s2 = svc.ApplyPatch(s.Token, new InvoiceDraftDelta { Target = "p13b", Value = JToken.FromObject(false) });
+
+        Assert.Equal(119m, s2!.Sums.TotalGross);             // VAT restored
+        Assert.Equal(19m, s2.Sums.VatByRate["19"]);
+    }
+
+    [Fact]
+    public void ApplyPatch_BlockReplace_InsertsWhenBlockIsNew()
+    {
+        var (svc, _, _) = NewService();
+        var s = svc.OpenFromPayload(Payload(), "user1");
+
+        var newBlock = JObject.Parse(@"{'Id':'2','text':'Zusatz','itm':[{'id':'950','typ':'material','vt':30,'vv':5.7,'vat':'19%'}],
+                                        'items':[{'id':'950','type':'material','total_net':30,'vat':'19%'}]}");
+        var s2 = svc.ApplyPatch(s.Token, new InvoiceDraftDelta { Target = "block.replace", Ref = "2", Value = newBlock });
+
+        Assert.Equal(2, s2!.Req.Count);
+        Assert.Equal(130m, s2.Sums.TotalNet);                // 100 (block 1) + 30 (new block 2)
+        Assert.Equal(30m, s2.Sums.NetByBlock["2"]);
+    }
+
+    // fds__prepInvoice's [SetItmID] window function anchors on the still-unconverted (price 0)
+    // Set header: the header row's own SetItmId self-references its own id ('1'), never null —
+    // ApplyItemSetPrice must still recognize id-equality first and never treat the header as its
+    // own member (see ApplyItemSetPrice's id == Ref check).
+    private static JObject SetPayload() => JObject.Parse(@"{
+        'admin':{'p13b':false,'type':'r','paymentterms':'10wd'},
+        'new':{'invoiceemail':'a@b.de','invoiceaddress':'Weg 1','invoicetitle':'Rechnung'},
+        'req':[{'Id':'1','text':'Auftrag','itm':[
+                {'id':'1','typ':'set','vt':0,'vv':0,'vs':0,'vsv':0,'vat':'19%','SetItmId':'1'},
+                {'id':'2','typ':'material','vt':60,'vv':11.4,'vs':0,'vsv':0,'vat':'19%','SetItmId':'1'},
+                {'id':'3','typ':'material','vt':40,'vv':7.6,'vs':10,'vsv':1.9,'vat':'19%','SetItmId':'1'}],
+                'items':[{'id':'1','type':'set'},{'id':'2','type':'material','setId':'1','total_net':60,'vat':'19%'},
+                         {'id':'3','type':'material','setId':'1','total_net':40,'vat':'19%'}]}]
+    }");
+
+    // A fourth, unrelated item ('4') follows the set's members in the same block but was never
+    // attributed a SetItmId by fds__prepInvoice (it isn't part of the set) — it must stay untouched
+    // by the conversion, proving membership is driven purely by SetItmId, not row order/position.
+    private static JObject SetPayloadWithTrailingUnrelatedItem() => JObject.Parse(@"{
+        'admin':{'p13b':false,'type':'r','paymentterms':'10wd'},
+        'new':{'invoiceemail':'a@b.de','invoiceaddress':'Weg 1','invoicetitle':'Rechnung'},
+        'req':[{'Id':'1','text':'Auftrag','itm':[
+                {'id':'1','typ':'set','vt':0,'vv':0,'vs':0,'vsv':0,'vat':'19%','SetItmId':'1'},
+                {'id':'2','typ':'material','vt':60,'vv':11.4,'vs':0,'vsv':0,'vat':'19%','SetItmId':'1'},
+                {'id':'3','typ':'material','vt':40,'vv':7.6,'vs':10,'vsv':1.9,'vat':'19%','SetItmId':'1'},
+                {'id':'4','typ':'material','vt':25,'vv':4.75,'vs':0,'vsv':0,'vat':'19%','SetItmId':null}],
+                'items':[{'id':'1','type':'set'},{'id':'2','type':'material','setId':'1','total_net':60,'vat':'19%'},
+                         {'id':'3','type':'material','setId':'1','total_net':40,'vat':'19%'},
+                         {'id':'4','type':'material','total_net':25,'vat':'19%'}]}]
+    }");
+
+    [Fact]
+    public void ApplyPatch_ItemSetPrice_SumsMembersOntoHeaderAndNullsMembers()
+    {
+        var (svc, _, _) = NewService();
+        var s = svc.OpenFromPayload(SetPayload(), "user1");
+
+        var s2 = svc.ApplyPatch(s.Token, new InvoiceDraftDelta { Target = "item.setprice", Ref = "1" });
+
+        Assert.NotNull(s2);
+        Assert.Equal(1, s2!.Version);
+        var block = (JObject)s2.Req[0];
+        var lines = (JArray)block["itm"]!;
+        var header = lines.OfType<JObject>().Single(l => (string)l["id"]! == "1");
+        var m2 = lines.OfType<JObject>().Single(l => (string)l["id"]! == "2");
+        var m3 = lines.OfType<JObject>().Single(l => (string)l["id"]! == "3");
+
+        Assert.Equal(100m, header["vt"]!.Value<decimal>());   // 60 + 40
+        Assert.Equal(19m, header["vv"]!.Value<decimal>());    // 11.4 + 7.6
+        Assert.Equal(10m, header["vs"]!.Value<decimal>());
+        Assert.Equal(1.9m, header["vsv"]!.Value<decimal>());
+        Assert.Equal(JTokenType.Null, m2["vt"]!.Type);   // ADR 0009: members nulled (empty cell), not 0
+        Assert.Equal(JTokenType.Null, m2["vv"]!.Type);
+        Assert.Equal(JTokenType.Null, m3["vt"]!.Type);
+        Assert.Equal(JTokenType.Null, m3["vv"]!.Type);
+
+        // Total invoice sum is unchanged by the conversion (set price == sum of members).
+        Assert.Equal(100m, s2.Sums.TotalNet);
+        Assert.Equal(19m, s2.Sums.TotalVat);
+
+        var h = Assert.Single(s2.History);
+        Assert.Equal("item.setprice", h.Target);
+        Assert.Equal("1", h.Ref);
+        Assert.Equal("0", h.OldValue);
+        Assert.Equal("100", h.NewValue);
+    }
+
+    [Fact]
+    public void ApplyPatch_ItemSetPrice_UnknownRef_IsNoOp()
+    {
+        var (svc, _, _) = NewService();
+        var s = svc.OpenFromPayload(SetPayload(), "user1");
+
+        var s2 = svc.ApplyPatch(s.Token, new InvoiceDraftDelta { Target = "item.setprice", Ref = "999" });
+
+        Assert.NotNull(s2);
+        Assert.Equal(0, s2!.Version);
+        Assert.Empty(s2.History);
+    }
+
+    [Fact]
+    public void ApplyPatch_ItemSetPrice_RefNotASetHeader_IsNoOp()
+    {
+        var (svc, _, _) = NewService();
+        var s = svc.OpenFromPayload(SetPayload(), "user1");
+
+        var s2 = svc.ApplyPatch(s.Token, new InvoiceDraftDelta { Target = "item.setprice", Ref = "2" });
+
+        Assert.NotNull(s2);
+        Assert.Equal(0, s2!.Version);
+        Assert.Empty(s2.History);
+    }
+
+    [Fact]
+    public void ApplyPatch_ItemSetPrice_HeaderSelfReferencingSetItmId_NeverCountsHeaderAsOwnMember()
+    {
+        // Regression test: fds__prepInvoice no longer nulls out the header's own SetItmId (it
+        // self-references its own id). ApplyItemSetPrice must still sum exactly the two real
+        // members (100 net), not 3x by also including the header as if it were a member of itself.
+        var (svc, _, _) = NewService();
+        var s = svc.OpenFromPayload(SetPayload(), "user1");
+
+        var s2 = svc.ApplyPatch(s.Token, new InvoiceDraftDelta { Target = "item.setprice", Ref = "1" });
+
+        Assert.NotNull(s2);
+        var block = (JObject)s2!.Req[0];
+        var lines = (JArray)block["itm"]!;
+        var header = lines.OfType<JObject>().Single(l => (string)l["id"]! == "1");
+
+        Assert.Equal(100m, header["vt"]!.Value<decimal>());   // 60 + 40, not tripled by self-inclusion
+        Assert.Equal(100m, s2.Sums.TotalNet);
+    }
+
+    [Fact]
+    public void ApplyPatch_ItemSetPrice_UnrelatedItemAfterMembers_IsNeverSweptIntoSet()
+    {
+        // Regression test for the reported bug: an item after the set's real members in the same
+        // block, but with no SetItmId of its own, must stay fully priced and untouched — only
+        // items the server actually tagged with SetItmId == the header id are members.
+        var (svc, _, _) = NewService();
+        var s = svc.OpenFromPayload(SetPayloadWithTrailingUnrelatedItem(), "user1");
+
+        var s2 = svc.ApplyPatch(s.Token, new InvoiceDraftDelta { Target = "item.setprice", Ref = "1" });
+
+        Assert.NotNull(s2);
+        var block = (JObject)s2!.Req[0];
+        var lines = (JArray)block["itm"]!;
+        var header = lines.OfType<JObject>().Single(l => (string)l["id"]! == "1");
+        var m2 = lines.OfType<JObject>().Single(l => (string)l["id"]! == "2");
+        var m3 = lines.OfType<JObject>().Single(l => (string)l["id"]! == "3");
+        var other = lines.OfType<JObject>().Single(l => (string)l["id"]! == "4");
+
+        Assert.Equal(100m, header["vt"]!.Value<decimal>());   // only the real members (60 + 40)
+        Assert.Equal(JTokenType.Null, m2["vt"]!.Type);        // ADR 0009: nulled, not 0
+        Assert.Equal(JTokenType.Null, m3["vt"]!.Type);
+        Assert.Equal(25m, other["vt"]!.Value<decimal>());     // untouched — never part of the set
+        Assert.Equal(4.75m, other["vv"]!.Value<decimal>());
+
+        // Total invoice sum unaffected: 100 (set) + 25 (unrelated item) = 125.
+        Assert.Equal(125m, s2.Sums.TotalNet);
+    }
+
+    // ── Block set-price menu modes (ADR 0009): per-service-request-block, irreversible ──
+    private static JObject BlocksPayload() => JObject.Parse(@"{
+        'admin':{'p13b':false,'type':'r'},
+        'new':{'invoiceemail':'a@b.de','invoiceaddress':'Weg 1','invoicetitle':'Rechnung'},
+        'req':[
+          {'Id':'1','text':'Auftrag A','itm':[
+            {'id':'11','typ':'material','vt':60,'vv':11.4,'vs':0,'vsv':0,'vat':'19%'},
+            {'id':'12','typ':'service','vt':40,'vv':7.6,'vs':40,'vsv':7.6,'vat':'19%'}],
+            'items':[{'id':'11','type':'material','total_net':60,'vat':'19%'},
+                     {'id':'12','type':'service','total_net':40,'vat':'19%'}]},
+          {'Id':'2','text':'Auftrag B','itm':[
+            {'id':'21','typ':'material','vt':30,'vv':5.7,'vs':0,'vsv':0,'vat':'19%'}],
+            'items':[{'id':'21','type':'material','total_net':30,'vat':'19%'}]}]
+    }");
+
+    [Fact]
+    public void ApplyPatch_BlockSetPrice_InsertsSetRowPerBlock_NullsMembers_TotalUnchanged()
+    {
+        var (svc, _, _) = NewService();
+        var s = svc.OpenFromPayload(BlocksPayload(), "user1");
+        Assert.Equal(130m, s.Sums.TotalNet);   // 100 (A) + 30 (B)
+
+        var s2 = svc.ApplyPatch(s.Token, new InvoiceDraftDelta { Target = "block.setprice" });
+
+        Assert.NotNull(s2);
+        Assert.Equal(1, s2!.Version);
+
+        var linesA = (JArray)((JObject)s2.Req[0])["itm"]!;
+        Assert.Equal(3, linesA.Count);                          // set row + the two (nulled) members, kept
+        var setA = (JObject)linesA[0];
+        Assert.Equal("set", (string)setA["typ"]!);
+        Assert.Equal("bset_1", (string)setA["id"]!);
+        Assert.Equal(100m, setA["vt"]!.Value<decimal>());       // block sum
+        Assert.Equal(19m, setA["vv"]!.Value<decimal>());
+        Assert.Equal(40m, setA["vs"]!.Value<decimal>());        // service-net split preserved
+        Assert.Equal(7.6m, setA["vsv"]!.Value<decimal>());
+        var m11 = linesA.OfType<JObject>().Single(l => (string)l["id"]! == "11");
+        Assert.Equal(JTokenType.Null, m11["vt"]!.Type);         // ADR 0009: null (empty cell), not 0
+        Assert.Equal(JTokenType.Null, m11["vv"]!.Type);
+
+        // items contract mirrors it (PDF reads total_net from here).
+        var itemsA = (JArray)((JObject)s2.Req[0])["items"]!;
+        Assert.Equal("set", (string)((JObject)itemsA[0])["type"]!);
+        Assert.Equal(100m, ((JObject)itemsA[0])["total_net"]!.Value<decimal>());
+        Assert.Equal(JTokenType.Null, itemsA.OfType<JObject>().Single(i => (string)i["id"]! == "11")["total_net"]!.Type);
+
+        // second block converted too; total conserved.
+        Assert.Equal(30m, ((JObject)((JArray)((JObject)s2.Req[1])["itm"]!)[0])["vt"]!.Value<decimal>());
+        Assert.Equal(130m, s2.Sums.TotalNet);
+        Assert.Equal(24.7m, s2.Sums.TotalVat);
+    }
+
+    [Fact]
+    public void ApplyPatch_BlockSetOnly_InsertsSetRowPerBlock_RemovesMembers_TotalUnchanged()
+    {
+        var (svc, _, _) = NewService();
+        var s = svc.OpenFromPayload(BlocksPayload(), "user1");
+
+        var s2 = svc.ApplyPatch(s.Token, new InvoiceDraftDelta { Target = "block.setonly" });
+
+        Assert.NotNull(s2);
+        var linesA = (JArray)((JObject)s2!.Req[0])["itm"]!;
+        Assert.Single(linesA);                                  // members removed, only the set row remains
+        Assert.Equal("set", (string)((JObject)linesA[0])["typ"]!);
+        Assert.Equal(100m, ((JObject)linesA[0])["vt"]!.Value<decimal>());
+        Assert.Single((JArray)((JObject)s2.Req[0])["items"]!);
+        Assert.Equal(130m, s2.Sums.TotalNet);                   // total unchanged
+    }
+
+    [Fact]
+    public void ApplyPatch_BlockSetPrice_SetRowNotSweptIntoBuildSetDisplay()
+    {
+        // The block set row has no setId members -> HasSetMembers is false -> it renders flat
+        // (emphasised on its own, members null to blank), so BuildSetDisplay must not emit flags for it.
+        var (svc, _, _) = NewService();
+        var s = svc.OpenFromPayload(BlocksPayload(), "user1");
+        svc.ApplyPatch(s.Token, new InvoiceDraftDelta { Target = "block.setprice" });
+
+        var state = JObject.FromObject(svc.BuildState(svc.Get(s.Token)!));
+        var setDisplay = (JObject)state["setDisplay"]!;
+        Assert.False(setDisplay.ContainsKey("bset_1"));
+        Assert.Empty(setDisplay);
+    }
+
+    [Fact]
+    public void ApplyPatch_BlockSetPrice_EmptyOrUnpricedBlocks_IsNoOp()
+    {
+        var (svc, _, _) = NewService();
+        var s = svc.OpenFromPayload(JObject.Parse(@"{
+            'admin':{'p13b':false,'type':'r'},
+            'new':{'invoiceemail':'a@b.de','invoiceaddress':'Weg 1','invoicetitle':'Rechnung'},
+            'req':[{'Id':'1','text':'Leer','itm':[],'items':[]}]
+        }"), "user1");
+
+        var s2 = svc.ApplyPatch(s.Token, new InvoiceDraftDelta { Target = "block.setprice" });
+
+        Assert.NotNull(s2);
+        Assert.Equal(0, s2!.Version);     // nothing priced -> no-op
+        Assert.Empty(s2.History);
+    }
+
+    [Fact]
+    public void ApplyPatch_UnknownTarget_IsNoOp_NoVersionBumpNoHistory()
+    {
+        var (svc, _, _) = NewService();
+        var s = svc.OpenFromPayload(Payload(), "user1");
+
+        var s2 = svc.ApplyPatch(s.Token, new InvoiceDraftDelta { Target = "nonsense", Value = JToken.FromObject("x") });
+
+        Assert.NotNull(s2);
+        Assert.Equal(0, s2!.Version);
+        Assert.Empty(s2.History);
+    }
+
+    [Fact]
+    public void ApplyPatch_MultipleEdits_AccumulateHistoryInOrder()
+    {
+        var (svc, _, _) = NewService();
+        var s = svc.OpenFromPayload(Payload(), "user1");
+
+        svc.ApplyPatch(s.Token, new InvoiceDraftDelta { Target = "email", Value = JToken.FromObject("a1@x.de") });
+        svc.ApplyPatch(s.Token, new InvoiceDraftDelta { Target = "title", Value = JToken.FromObject("Titel 2") });
+        var s3 = svc.ApplyPatch(s.Token, new InvoiceDraftDelta { Target = "address", Value = JToken.FromObject("Adr 3") });
+
+        Assert.Equal(3, s3!.Version);
+        Assert.Equal(3, s3.History.Count);
+        Assert.Equal(new[] { "email", "title", "address" }, s3.History.Select(h => h.Target).ToArray());
+        Assert.Equal(new[] { 1, 2, 3 }, s3.History.Select(h => h.Version).ToArray());
+    }
+
+    [Fact]
+    public void BuildState_ExposesPayloadSumsValidationAndVersion()
+    {
+        var (svc, _, _) = NewService();
+        var s = svc.OpenFromPayload(Payload(), "user1");
+        svc.ApplyPatch(s.Token, new InvoiceDraftDelta { Target = "email", Value = JToken.FromObject("x@y.de") });
+
+        var state = JObject.FromObject(svc.BuildState(svc.Get(s.Token)!));
+
+        Assert.Equal(1, state["version"]!.Value<int>());
+        Assert.Equal(100m, state["sums"]!["total_net"]!.Value<decimal>());
+        Assert.Equal(119m, state["sums"]!["total_gross"]!.Value<decimal>());
+        Assert.Equal(19m, state["sums"]!["vat"]!["19"]!.Value<decimal>());
+        Assert.Single((JArray)state["req"]!);
+        Assert.Equal(1, state["historyCount"]!.Value<int>());
+        Assert.NotNull(state["validation"]);
+    }
+
+    [Fact]
+    public async Task FlushToDbAsync_ExistingInvId_UpdatesInsteadOfCreates()
+    {
+        var (svc, inv, _) = NewService();
+        var payload = Payload();
+        payload["invid"] = "INV7";
+        var s = svc.OpenFromPayload(payload, "user1");
+
+        await svc.FlushToDbAsync(s.Token, "user1", null!);
+
+        Assert.True(inv.LastChange);   // prior InvId → update path
+    }
+
+    [Fact]
+    public async Task FlushToDbAsync_MapsInvoiceOptionsFrom13bAndSetmode()
+    {
+        var (svc, inv, _) = NewService();
+        var payload = Payload();
+        payload["admin"]!["p13b"] = true;
+        payload["admin"]!["setmode"] = "setonly";
+        var s = svc.OpenFromPayload(payload, "user1");
+
+        await svc.FlushToDbAsync(s.Token, "user1", null!);
+
+        var options = inv.Registered!.BuildInvoiceParams(change: false, invId: "")
+            .First(p => p.ParameterName == "@InvoiceOptions").Value?.ToString() ?? "";
+        Assert.Contains("§13b", options);
+        Assert.Contains("setmode:setonly", options);
+    }
+
+    [Fact]
+    public void RenderPreview_SynthesizesDraftRegistrationFromSession()
+    {
+        var (svc, inv, _) = NewService();
+        var s = svc.OpenFromPayload(Payload(), "user1");
+
+        var doc = svc.RenderPreview(s.Token);
+
+        Assert.NotNull(doc);
+        Assert.True(inv.PreviewDraft);                          // always rendered as a draft
+        var reg = inv.PreviewInvoice!.InvoiceRegistration!;
+        Assert.Equal("Rechnung", reg.getString("InvoiceTitle"));
+        Assert.Equal("Weg 1", reg.getString("SendToAddress"));
+        Assert.Equal("a@b.de", reg.getString("SendToEmail"));
+        Assert.Equal("19", reg.getString("InvoiceVAT_1"));     // rate synthesised from server sums
+        Assert.True(inv.PreviewInvoice.IsDraft);
+    }
+
+    [Fact]
+    public void RenderPreview_UnknownToken_ReturnsNull()
+    {
+        var (svc, _, _) = NewService();
+        Assert.Null(svc.RenderPreview("ghost"));
+    }
+
+    [Fact]
+    public void Close_RemovesSession_ThenReportsFalse()
+    {
+        var (svc, _, _) = NewService();
+        var s = svc.OpenFromPayload(Payload(), "user1");
+
+        Assert.True(svc.Close(s.Token));
+        Assert.Null(svc.Get(s.Token));
+        Assert.False(svc.Close(s.Token));
+    }
+
+    // ── HTML sanitisation (values must never reach the DB/PDF wrapped in tags) ─
+    [Theory]
+    [InlineData("provisionperiod", "provisionperiod")]
+    [InlineData("title", "invoicetitle")]
+    [InlineData("email", "invoiceemail")]
+    public void ApplyPatch_ScalarField_StripsHtmlWrapper(string target, string newKey)
+    {
+        var (svc, _, _) = NewService();
+        var s = svc.OpenFromPayload(Payload(), "user1");
+
+        var s2 = svc.ApplyPatch(s.Token, new InvoiceDraftDelta { Target = target, Value = JToken.FromObject("<p>18.06.2026</p>") });
+
+        Assert.Equal("18.06.2026", s2!.New[newKey]!.Value<string>());   // no <p> tags stored
+        Assert.Equal("18.06.2026", Assert.Single(s2.History).NewValue);
+    }
+
+    [Fact]
+    public void ApplyPatch_Address_MultilineHtml_KeepsLineBreaks()
+    {
+        var (svc, _, _) = NewService();
+        var s = svc.OpenFromPayload(Payload(), "user1");
+
+        var s2 = svc.ApplyPatch(s.Token, new InvoiceDraftDelta
+        {
+            Target = "address",
+            Value = JToken.FromObject("<p>Firma AG</p><p>Weg 1<br>5080 Laufenburg</p>")
+        });
+
+        Assert.Equal("Firma AG\nWeg 1\n5080 Laufenburg", s2!.New["invoiceaddress"]!.Value<string>());
+    }
+
+    [Fact]
+    public void ApplyPatch_ScalarField_DecodesEntities()
+    {
+        var (svc, _, _) = NewService();
+        var s = svc.OpenFromPayload(Payload(), "user1");
+
+        var s2 = svc.ApplyPatch(s.Token, new InvoiceDraftDelta { Target = "title", Value = JToken.FromObject("Tom &amp; Jerry") });
+
+        Assert.Equal("Tom & Jerry", s2!.New["invoicetitle"]!.Value<string>());
+    }
+
+    [Fact]
+    public void ApplyPatch_ProvisionLocation_SanitisesAndMirrorsLoc()
+    {
+        var (svc, _, _) = NewService();
+        var s = svc.OpenFromPayload(Payload(), "user1");
+
+        var s2 = svc.ApplyPatch(s.Token, new InvoiceDraftDelta { Target = "provisionlocation", Value = JToken.FromObject("<p>Baustelle 7</p>") });
+
+        Assert.Equal("Baustelle 7", s2!.New["provisionlocation"]!.Value<string>());
+        Assert.Equal("Baustelle 7", s2.New["loc"]!.Value<string>());
+    }
+
+    // ── Change history records the changed field, not the whole block JSON ─────
+    [Fact]
+    public void ApplyPatch_BlockReplace_HistoryNewValueIsSectionText_NotJson()
+    {
+        var (svc, _, _) = NewService();
+        var s = svc.OpenFromPayload(Payload(), "user1");
+
+        var newBlock = JObject.Parse(@"{'Id':'1','text':'<p>Neue Überschrift</p>',
+            'itm':[{'id':'900','typ':'material','vt':100,'vv':19,'vat':'19%'}],
+            'items':[{'id':'900','type':'material','total_net':100,'vat':'19%'}]}");
+        var s2 = svc.ApplyPatch(s.Token, new InvoiceDraftDelta { Target = "block.replace", Ref = "1", Value = newBlock });
+
+        var h = Assert.Single(s2!.History);
+        Assert.Equal("Neue Überschrift", h.NewValue);      // the heading, sanitised — never the block JSON
+        Assert.DoesNotContain("{", h.NewValue);
+        Assert.Equal("Auftrag", h.OldValue);
+        // and the cached block text is stored clean too
+        Assert.Equal("Neue Überschrift", ((JObject)s2.Req[0])["text"]!.Value<string>());
+    }
+
+    // ── Section reorder ───────────────────────────────────────────────────────
+    private static JObject TwoBlockPayload() => JObject.Parse(@"{
+        'admin':{'p13b':false,'type':'r'},
+        'new':{'invoiceemail':'a@b.de','invoiceaddress':'Weg 1'},
+        'req':[
+          {'Id':'1','text':'A','itm':[{'id':'900','typ':'material','vt':100,'vv':19,'vat':'19%'}],'items':[{'id':'900','type':'material','total_net':100,'vat':'19%'}]},
+          {'Id':'2','text':'B','itm':[{'id':'950','typ':'material','vt':30,'vv':5.7,'vat':'19%'}],'items':[{'id':'950','type':'material','total_net':30,'vat':'19%'}]}
+        ]}");
+
+    [Fact]
+    public void ApplyPatch_BlockOrder_ReordersReqAndRenumbersPositions()
+    {
+        var (svc, _, _) = NewService();
+        var s = svc.OpenFromPayload(TwoBlockPayload(), "user1");
+        Assert.Equal(new[] { "1", "2" }, s.Req.Select(b => b["Id"]!.Value<string>()).ToArray());
+
+        var s2 = svc.ApplyPatch(s.Token, new InvoiceDraftDelta { Target = "block.order", Value = JArray.Parse("['2','1']") });
+
+        Assert.Equal(new[] { "2", "1" }, s2!.Req.Select(b => b["Id"]!.Value<string>()).ToArray());
+        Assert.Equal("1", ((JObject)((JArray)((JObject)s2.Req[0])["itm"]!)[0])["p"]!.ToString());   // block 2's item now position 1
+        Assert.Equal(130m, s2.Sums.TotalNet);                                                        // totals unaffected by reorder
+        var h = Assert.Single(s2.History);
+        Assert.Equal("1,2", h.OldValue);
+        Assert.Equal("2,1", h.NewValue);
+    }
+
+    [Fact]
+    public void ApplyPatch_BlockOrder_UnchangedSequence_IsNoOp()
+    {
+        var (svc, _, _) = NewService();
+        var s = svc.OpenFromPayload(TwoBlockPayload(), "user1");
+
+        var s2 = svc.ApplyPatch(s.Token, new InvoiceDraftDelta { Target = "block.order", Value = JArray.Parse("['1','2']") });
+
+        Assert.Equal(0, s2!.Version);      // no-op: no version bump, no history
+        Assert.Empty(s2.History);
+    }
+
+    [Fact]
+    public void ApplyPatch_BlockOrder_UnknownIds_KeepMentionedFirstThenRest()
+    {
+        var (svc, _, _) = NewService();
+        var s = svc.OpenFromPayload(TwoBlockPayload(), "user1");
+
+        // Only name block 2; block 1 is unmentioned and must be kept (appended after).
+        var s2 = svc.ApplyPatch(s.Token, new InvoiceDraftDelta { Target = "block.order", Value = JArray.Parse("['2','ghost']") });
+
+        Assert.Equal(new[] { "2", "1" }, s2!.Req.Select(b => b["Id"]!.Value<string>()).ToArray());
+    }
+
+    // ── Multiple VAT rates aggregate independently (ADR 0008: server owns every tax sum) ──
+    private static JObject MultiRatePayload() => JObject.Parse(@"{
+        'admin':{'p13b':false,'type':'r'},
+        'new':{'invoiceemail':'a@b.de','invoiceaddress':'Weg 1'},
+        'req':[
+          {'Id':'1','text':'A','itm':[
+              {'id':'900','typ':'material','vt':100,'vv':19,'vat':'19%'},
+              {'id':'901','typ':'material','vt':200,'vv':14,'vat':'7%'},
+              {'id':'902','typ':'material','vt':50,'vv':0,'vat':'0%'}],
+           'items':[{'id':'900','type':'material','total_net':100,'vat':'19%'},
+                     {'id':'901','type':'material','total_net':200,'vat':'7%'},
+                     {'id':'902','type':'material','total_net':50,'vat':'0%'}]}
+        ]}");
+
+    [Fact]
+    public void OpenFromPayload_MultipleVatRates_GroupsSumsPerRate()
+    {
+        var (svc, _, _) = NewService();
+        var s = svc.OpenFromPayload(MultiRatePayload(), "user1");
+
+        Assert.Equal(350m, s.Sums.TotalNet);
+        Assert.Equal(33m, s.Sums.TotalVat);
+        Assert.Equal(383m, s.Sums.TotalGross);
+        Assert.Equal(19m, s.Sums.VatByRate["19"]);
+        Assert.Equal(14m, s.Sums.VatByRate["7"]);
+        Assert.False(s.Sums.VatByRate.ContainsKey("0"));   // zero-rate contributes no VAT key (mirrors calculator)
+    }
+
+    [Fact]
+    public void ApplyPatch_BlockReplace_MultiRate_RecomputesEachRateIndependently()
+    {
+        var (svc, _, _) = NewService();
+        var s = svc.OpenFromPayload(MultiRatePayload(), "user1");
+
+        // Halve the 7%-rate line's net/VAT via a block replace; the 19% bucket must stay untouched.
+        var newBlock = JObject.Parse(@"{'Id':'1','text':'A','itm':[
+              {'id':'900','typ':'material','vt':100,'vv':19,'vat':'19%'},
+              {'id':'901','typ':'material','vt':100,'vv':7,'vat':'7%'},
+              {'id':'902','typ':'material','vt':50,'vv':0,'vat':'0%'}],
+           'items':[]}");
+        var s2 = svc.ApplyPatch(s.Token, new InvoiceDraftDelta { Target = "block.replace", Ref = "1", Value = newBlock });
+
+        Assert.Equal(19m, s2!.Sums.VatByRate["19"]);   // unchanged
+        Assert.Equal(7m, s2.Sums.VatByRate["7"]);      // recomputed from new line
+        Assert.Equal(250m, s2.Sums.TotalNet);
+        Assert.Equal(26m, s2.Sums.TotalVat);
+    }
+
+    // ── BuildSetDisplay reflects both set-pricing modes (mirrors the PDF's InvoiceSetPricing) ──
+    // SetPayload()'s header item is still unconverted (own total_net == 0, as delivered by
+    // fds__prepInvoice) — until the set-item switch (ApplyItemSetPrice) actually gives it its own
+    // price, InvoiceSetPricing.Build must not apply the chosen setmode yet: header stays blank and
+    // each member keeps showing its own individual price.
+    [Theory]
+    [InlineData("setprice")]
+    [InlineData("setonly")]
+    public void BuildState_SetDisplay_UnconvertedSet_HeaderBlankMembersIndividuallyPriced(string setmode)
+    {
+        var (svc, _, _) = NewService();
+        var payload = SetPayload();
+        payload["admin"]!["setmode"] = setmode;
+        var s = svc.OpenFromPayload(payload, "user1");
+
+        var state = JObject.FromObject(svc.BuildState(s));
+        var setDisplay = (JObject)state["setDisplay"]!;
+
+        Assert.False(setDisplay["1"]!["p"]!.Value<bool>());   // header not priced yet
+        Assert.True(setDisplay["2"]!["p"]!.Value<bool>());    // member 2 keeps its own price
+        Assert.True(setDisplay["3"]!["p"]!.Value<bool>());    // member 3 keeps its own price
+    }
+
+    // Once converted (ApplyItemSetPrice has given the header its own price), the chosen setmode
+    // takes effect: SetPrice blanks the members (still present in the map); SetOnly drops them
+    // from the map entirely.
+    [Theory]
+    [InlineData("setprice", true, false)]     // header priced, member 2 blank
+    [InlineData("setonly", true, false)]       // header priced; member 2 dropped entirely (absent from map)
+    public void BuildState_SetDisplay_ConvertedSet_ReflectsSetmodeForHeaderAndMember(string setmode, bool headerShown, bool memberShown)
+    {
+        var (svc, _, _) = NewService();
+        var payload = SetPayload();
+        payload["admin"]!["setmode"] = setmode;
+        var s = svc.OpenFromPayload(payload, "user1");
+        svc.ApplyPatch(s.Token, new InvoiceDraftDelta { Target = "item.setprice", Ref = "1" });   // convert the set first
+
+        var state = JObject.FromObject(svc.BuildState(s));
+        var setDisplay = (JObject)state["setDisplay"]!;
+
+        Assert.Equal(headerShown, setDisplay["1"]!["p"]!.Value<bool>());
+        if (setmode == "setonly")
+            Assert.False(setDisplay.ContainsKey("2"));      // member removed from the display entirely
+        else
+            Assert.Equal(memberShown, setDisplay["2"]!["p"]!.Value<bool>());
+    }
+
+    // ── Full lifecycle recalculation: several edits of different kinds land in one consistent recompute ──
+    [Fact]
+    public void ApplyPatch_FullEditSequence_TextReorderSetPriceAndTaxToggle_EndsConsistent()
+    {
+        var (svc, _, _) = NewService();
+        var s = svc.OpenFromPayload(TwoBlockPayload(), "user1");
+
+        // 1) text change
+        svc.ApplyPatch(s.Token, new InvoiceDraftDelta { Target = "title", Value = JToken.FromObject("Endabrechnung") });
+        // 2) reorder sections
+        svc.ApplyPatch(s.Token, new InvoiceDraftDelta { Target = "block.order", Value = JArray.Parse("['2','1']") });
+        // 3) toggle reverse-charge on, then off again (settings roundtrip)
+        svc.ApplyPatch(s.Token, new InvoiceDraftDelta { Target = "p13b", Value = JToken.FromObject(true) });
+        var final = svc.ApplyPatch(s.Token, new InvoiceDraftDelta { Target = "p13b", Value = JToken.FromObject(false) });
+
+        Assert.NotNull(final);
+        Assert.Equal("Endabrechnung", final!.New["invoicetitle"]!.Value<string>());
+        Assert.Equal(new[] { "2", "1" }, final.Req.Select(b => b["Id"]!.Value<string>()).ToArray());
+        Assert.Equal("1", ((JObject)((JArray)((JObject)final.Req[0])["itm"]!)[0])["p"]!.ToString());  // renumbered after reorder
+        Assert.Equal(130m, final.Sums.TotalNet);          // totals stable across the whole sequence
+        Assert.Equal(24.7m, final.Sums.TotalVat);         // VAT restored after the toggle roundtrip
+        Assert.Equal(4, final.History.Count);
+        Assert.DoesNotContain(final.ValidationMessages, m => m.Severity == "error");
+    }
+}

Fuchs.Tests/InvoiceOptionsTests.cs

@@ -1,4 +1,4 @@
-using System;
+using System;
 using System.Collections.Generic;
 using System.Linq;
 using Fuchs.intranet;
@@ -31,16 +31,25 @@ public class InvoiceOptionsTests
         => Assert.Equal("", InvoiceOptionsFor(new { type = "r" }));
 
     [Fact]
-    public void DefaultSetPrice_OmitsToken()
-        => Assert.Equal("", InvoiceOptionsFor(new { type = "r", setmode = "setprice" }));
+    public void ExplicitDefaultSetPrice_EmitsToken()
+        // An explicit choice of the default mode must still be persisted — otherwise it is
+        // indistinguishable from an invoice that was never switched to set-pricing at all
+        // (the editor relies on this to hide the "Set-Preisanzeige" menu entry once chosen).
+        => Assert.Equal("setmode:setprice", InvoiceOptionsFor(new { type = "r", setmode = "setprice" }));
 
     [Theory]
-    [InlineData("itemprices", "setmode:itemprices")]
     [InlineData("setonly",    "setmode:setonly")]
-    [InlineData("ITEMPRICES", "setmode:itemprices")] // case-insensitive
+    [InlineData("SETONLY",    "setmode:setonly")] // case-insensitive
     public void SetMode_EmitsToken(string mode, string expected)
         => Assert.Equal(expected, InvoiceOptionsFor(new { type = "r", setmode = mode }));
 
+    [Fact]
+    public void RemovedItemPricesMode_OmitsToken()
+        // "itemprices" was a valid mode before the button/mode was removed. Any invoice options
+        // still carrying the stale value (or a client re-posting it) must not be persisted as a
+        // recognized token — it is treated the same as an unknown/garbage mode.
+        => Assert.Equal("", InvoiceOptionsFor(new { type = "r", setmode = "itemprices" }));
+
     [Fact]
     public void UnknownSetMode_OmitsToken()
         => Assert.Equal("", InvoiceOptionsFor(new { type = "r", setmode = "garbage" }));
@@ -103,9 +112,11 @@ public class InvoiceOptionsTests
     public void ModeFromInvoiceOptions_RoundTripsBackendEmission()
     {
         // The token this side emits must parse back to the same mode on the PDF side.
-        Assert.Equal(SetDisplayMode.ItemPrices,
-            InvoiceSetPricing.ModeFromInvoiceOptions(InvoiceOptionsFor(new { type = "r", setmode = "itemprices" })));
         Assert.Equal(SetDisplayMode.SetOnly,
             InvoiceSetPricing.ModeFromInvoiceOptions(InvoiceOptionsFor(new { type = "r", p13b = true, setmode = "setonly" })));
+        // A removed mode never round-trips as itself — it is never persisted, so reading it back
+        // always yields the default SetPrice.
+        Assert.Equal(SetDisplayMode.SetPrice,
+            InvoiceSetPricing.ModeFromInvoiceOptions(InvoiceOptionsFor(new { type = "r", setmode = "itemprices" })));
     }
 }

Fuchs.Tests/InvoiceRecipientAddressTests.cs

@@ -0,0 +1,104 @@
+using Fuchs.Services;
+using Newtonsoft.Json.Linq;
+using Xunit;
+
+namespace Fuchs.Tests;
+
+/// <summary>
+/// Pure-logic tests for the structured invoice recipient address: free-text composition for the
+/// PDF, EN 16931 / DATEV conformity detection, effortless B2C (no VAT id), and JSON round-tripping
+/// through the <c>CustomValues</c> blob. See ADR 0012.
+/// </summary>
+public class InvoiceRecipientAddressTests
+{
+    private static InvoiceRecipientAddress FullB2B() => new()
+    {
+        Name = "Muster GmbH",
+        Contact = "Frau Schmidt",
+        Street = "Hauptstraße 1",
+        PostalCode = "40223",
+        City = "Düsseldorf",
+        CountryCode = "DE",
+        VatId = "DE123456789",
+    };
+
+    [Fact]
+    public void Compose_DomesticFullAddress_OmitsCountryLineAndVatId()
+    {
+        var text = FullB2B().Compose();
+        Assert.Equal("Muster GmbH\nz.Hd. Frau Schmidt\nHauptstraße 1\n40223 Düsseldorf", text);
+        Assert.DoesNotContain("DE123456789", text); // VAT id never in the postal block
+        Assert.DoesNotContain("\nDE", text);        // domestic country code suppressed
+    }
+
+    [Fact]
+    public void Compose_ForeignCountry_AppendsCountryCodeLine()
+    {
+        var addr = FullB2B();
+        addr.CountryCode = "AT";
+        addr.City = "Wien";
+        addr.PostalCode = "1010";
+        Assert.EndsWith("1010 Wien\nAT", addr.Compose());
+    }
+
+    [Fact]
+    public void PrivatePerson_NoVatId_IsB2CAndStillEn16931Conformant()
+    {
+        var addr = new InvoiceRecipientAddress
+        {
+            Name = "Max Mustermann",
+            Street = "Weg 2",
+            PostalCode = "50667",
+            City = "Köln",
+            CountryCode = "DE",
+            // no VatId
+        };
+        Assert.True(addr.IsPrivatePerson);
+        Assert.True(addr.IsEn16931Conformant);
+        Assert.Empty(addr.MissingForEn16931());
+    }
+
+    [Theory]
+    [InlineData("", "DE", "Köln", new[] { "Name" })]
+    [InlineData("Firma", "", "Köln", new[] { "Land" })]
+    [InlineData("Firma", "DE", "", new[] { "Ort/PLZ" })]
+    public void MissingForEn16931_FlagsMandatoryGaps(string name, string country, string city, string[] expected)
+    {
+        var addr = new InvoiceRecipientAddress { Name = name, CountryCode = country, City = city };
+        Assert.Equal(expected, addr.MissingForEn16931());
+        Assert.False(addr.IsEn16931Conformant);
+    }
+
+    [Fact]
+    public void FromJson_AcceptsAlternateKeys()
+    {
+        var addr = InvoiceRecipientAddress.FromJson(JObject.Parse(
+            @"{'name':'X','plz':'12345','ort':'Ort','country':'de','ustid':'DE9'}"));
+        Assert.Equal("12345", addr.PostalCode);
+        Assert.Equal("Ort", addr.City);
+        Assert.Equal("DE", addr.CountryCode); // uppercased
+        Assert.Equal("DE9", addr.VatId);
+    }
+
+    [Fact]
+    public void FromCustomValues_RoundTripsThroughTheBlob()
+    {
+        var cv = new JObject
+        {
+            ["contactName"] = "someone",
+            [InvoiceRecipientAddress.CustomValuesKey] = FullB2B().ToJson(),
+        };
+        var parsed = InvoiceRecipientAddress.FromCustomValues(cv.ToString());
+        Assert.NotNull(parsed);
+        Assert.Equal("Muster GmbH", parsed!.Name);
+        Assert.Equal("DE123456789", parsed.VatId);
+    }
+
+    [Fact]
+    public void FromCustomValues_ReturnsNull_WhenNoStructuredAddressPresent()
+    {
+        Assert.Null(InvoiceRecipientAddress.FromCustomValues(@"{'contactName':'x'}"));
+        Assert.Null(InvoiceRecipientAddress.FromCustomValues(""));
+        Assert.Null(InvoiceRecipientAddress.FromCustomValues("not json"));
+    }
+}

Fuchs.Tests/InvoiceSetPricingTests.cs

@@ -1,4 +1,4 @@
-using System.Collections.Generic;
+using System.Collections.Generic;
 using System.Linq;
 using Fuchs.intranet;
 using Xunit;
@@ -40,11 +40,11 @@ public class InvoiceSetPricingTests
 
     // ── Mode parsing ────────────────────────────────────────────────────────
     [Theory]
-    [InlineData("itemprices", SetDisplayMode.ItemPrices)]
-    [InlineData("items",      SetDisplayMode.ItemPrices)]
     [InlineData("setonly",    SetDisplayMode.SetOnly)]
+    [InlineData("set_only",   SetDisplayMode.SetOnly)]
     [InlineData("setprice",   SetDisplayMode.SetPrice)]
     [InlineData("",           SetDisplayMode.SetPrice)]
+    [InlineData("itemprices", SetDisplayMode.SetPrice)] // removed mode — falls back to default, never throws
     [InlineData("garbage",    SetDisplayMode.SetPrice)]
     public void ParseMode_Works(string raw, SetDisplayMode expected)
         => Assert.Equal(expected, InvoiceSetPricing.ParseMode(raw));
@@ -52,10 +52,12 @@ public class InvoiceSetPricingTests
     [Fact]
     public void ModeFromInvoiceOptions_ReadsToken()
     {
-        Assert.Equal(SetDisplayMode.ItemPrices, InvoiceSetPricing.ModeFromInvoiceOptions("§13b,setmode:itemprices"));
-        Assert.Equal(SetDisplayMode.SetOnly,    InvoiceSetPricing.ModeFromInvoiceOptions("setmode:setonly"));
+        Assert.Equal(SetDisplayMode.SetOnly,  InvoiceSetPricing.ModeFromInvoiceOptions("§13b,setmode:setonly"));
         Assert.Equal(SetDisplayMode.SetPrice, InvoiceSetPricing.ModeFromInvoiceOptions("§13b"));      // default
         Assert.Equal(SetDisplayMode.SetPrice, InvoiceSetPricing.ModeFromInvoiceOptions(null));
+        // A stale/removed "itemprices" token (e.g. from an invoice created before the mode was
+        // dropped) must not throw — it degrades gracefully to the default SetPrice mode.
+        Assert.Equal(SetDisplayMode.SetPrice, InvoiceSetPricing.ModeFromInvoiceOptions("setmode:itemprices"));
     }
 
     [Fact]
@@ -85,22 +87,6 @@ public class InvoiceSetPricingTests
         Assert.Equal(50.00m, lines[3].TotalNet);
     }
 
-    // ── ItemPrices: members priced, set header blank ──────────────────────────
-    [Fact]
-    public void Build_ItemPrices_MembersPricedHeaderBlank()
-    {
-        var lines = InvoiceSetPricing.Build(Sample(), SetDisplayMode.ItemPrices);
-
-        Assert.Equal(4, lines.Count);
-        Assert.True(lines[0].IsSetHeader);
-        Assert.False(lines[0].ShowPrice);                   // set header is just a title now
-        Assert.True(lines[1].ShowPrice);
-        Assert.Equal(600.00m, lines[1].TotalNet);
-        Assert.True(lines[2].ShowPrice);
-        Assert.Equal(400.00m, lines[2].TotalNet);
-        Assert.True(lines[3].ShowPrice);                    // standalone
-    }
-
     // ── SetOnly: members removed ──────────────────────────────────────────────
     [Fact]
     public void Build_SetOnly_RemovesMembers()
@@ -115,18 +101,45 @@ public class InvoiceSetPricingTests
         Assert.Equal("Anfahrt", lines[1].Title);
     }
 
-    // ── Set price falls back to sum of members when header total is 0 ─────────
+    // ── Unconverted set (header total still 0): shown blank, members individually priced ──
     [Fact]
-    public void Build_HeaderTotalZero_UsesSumOfMembers()
+    public void Build_HeaderTotalZero_UnconvertedSet_HeaderBlankMembersPriced()
     {
         var items = new List<Dictionary<string, object?>>
         {
-            SetHeader("7", "Set ohne Preis"),               // total 0
+            SetHeader("7", "Set ohne Preis"),               // total 0 — not yet converted
             Member("7", "A", "120.00", "120.00"),
             Member("7", "B", "80.00",  "80.00")
         };
         var lines = InvoiceSetPricing.Build(items, SetDisplayMode.SetPrice);
-        Assert.Equal(200.00m, lines[0].TotalNet);           // 120 + 80
+
+        Assert.Equal(3, lines.Count);
+        Assert.True(lines[0].IsSetHeader);
+        Assert.False(lines[0].ShowPrice);                   // header not priced yet
+        Assert.Equal(0m, lines[0].TotalNet);
+
+        Assert.True(lines[1].ShowPrice);                    // members keep their own price
+        Assert.Equal(120.00m, lines[1].TotalNet);
+        Assert.True(lines[2].ShowPrice);
+        Assert.Equal(80.00m, lines[2].TotalNet);
+    }
+
+    // ── SetOnly on an unconverted set also just passes items through unchanged ──
+    [Fact]
+    public void Build_HeaderTotalZero_UnconvertedSet_SetOnlyModeStillPassesThrough()
+    {
+        var items = new List<Dictionary<string, object?>>
+        {
+            SetHeader("7", "Set ohne Preis"),
+            Member("7", "A", "120.00", "120.00"),
+            Member("7", "B", "80.00",  "80.00")
+        };
+        var lines = InvoiceSetPricing.Build(items, SetDisplayMode.SetOnly);
+
+        Assert.Equal(3, lines.Count);                       // members not dropped before conversion
+        Assert.False(lines[0].ShowPrice);
+        Assert.True(lines[1].ShowPrice);
+        Assert.True(lines[2].ShowPrice);
     }
 
     // ── No sets: pass-through unchanged ───────────────────────────────────────
@@ -164,7 +177,7 @@ public class InvoiceSetPricingTests
     }
 
     [Fact]
-    public void Build_TextLine_AsSetMember_NoPriceEvenInItemPrices()
+    public void Build_TextLine_AsSetMember_NoPriceInSetPriceMode()
     {
         var items = new List<Dictionary<string, object?>>
         {
@@ -172,10 +185,10 @@ public class InvoiceSetPricingTests
             new() { ["type"] = "title", ["setId"] = "10", ["title"] = "Hinweis", ["total_net"] = "" },
             Member("10", "Waschbecken", "600.00", "600.00")
         };
-        var lines = InvoiceSetPricing.Build(items, SetDisplayMode.ItemPrices);
+        var lines = InvoiceSetPricing.Build(items, SetDisplayMode.SetPrice);
         var note = lines.First(l => l.Title == "Hinweis");
-        Assert.False(note.ShowPrice);       // text member stays blank
-        Assert.True(lines.First(l => l.Title == "Waschbecken").ShowPrice);
+        Assert.False(note.ShowPrice);       // text member stays blank (already blank in SetPrice mode)
+        Assert.False(lines.First(l => l.Title == "Waschbecken").ShowPrice); // members blank in SetPrice mode too
     }
 
     // ── Set price equals sum of member prices across modes (no double counting) ─

Fuchs.Tests/MFRClientTests.cs

@@ -55,6 +55,18 @@ public class MFRClientConfigTests
         Assert.Equal("", config.LogoutAddress);
         Assert.Equal("", config.TokenCookieName);
     }
+
+    // Regression: an empty/missing host used to be silently turned into "https:///odata/"
+    // (empty authority), which only failed much later inside RestSharp with a cryptic
+    // "Invalid URI: The hostname could not be parsed." Fail fast at construction instead.
+    [Theory]
+    [InlineData(null)]
+    [InlineData("")]
+    [InlineData("   ")]
+    public void Constructor_WithMissingHost_ThrowsArgumentException(string? url)
+    {
+        Assert.Throws<ArgumentException>(() => new MFRClientConfig(url!));
+    }
 }
 
 public class MFRClientCredentialsTests

Fuchs.Tests/PdfPipelineTests.cs

@@ -0,0 +1,370 @@
+using System;
+using System.Collections.Generic;
+using System.IO;
+using System.Linq;
+using System.Text;
+using System.Threading.Tasks;
+using eRechnungLib;
+using eRechnungLib.Model;
+using eRechnungLib.Model.CodeLists;
+using eRechnungLib.Profiles;
+using Fuchs.intranet;
+using Fuchs.Services;
+using MigraDoc.DocumentObjectModel;
+using MigraDoc.Rendering;
+using Microsoft.Extensions.Configuration;
+using PdfSharp.Pdf.IO;
+using Xunit;
+
+namespace Fuchs.Tests;
+
+/// <summary>
+/// Exercises the invoice PDF pipeline end to end:
+///   1. a visual invoice PDF is produced with PdfSharp/MigraDoc,
+///   2. it is rasterised to preview images via Spire (the licensed path used by <c>sprep</c>),
+///   3. it is turned into a formally valid eRechnung (ZUGFeRD/Factur-X hybrid + XRechnung XML)
+///      via eRechnungLib — the direction the project is moving in (all invoices as eRechnung).
+/// Both an intentionally succeeding and an intentionally failing conversion path are covered.
+/// </summary>
+public class PdfPipelineTests
+{
+    // ── Stage 1 helper: a "dummy" visual invoice PDF built purely with PdfSharp/MigraDoc ──
+    private static byte[] BuildDummyPdfWithPdfSharp()
+    {
+        // Same font resolver the production render path installs (PdfSharp 6 no longer
+        // resolves system fonts on its own).
+        if (PdfSharp.Fonts.GlobalFontSettings.FontResolver is null ||
+            PdfSharp.Fonts.GlobalFontSettings.FontResolver.GetType() != typeof(OCORE_web_pdf.pdf.OCOREFontResolver))
+        {
+            PdfSharp.Fonts.GlobalFontSettings.FontResolver = new OCORE_web_pdf.pdf.OCOREFontResolver();
+        }
+
+        var doc = new Document();
+        doc.Info.Title = "Dummy Rechnung";
+        var normal = doc.Styles["Normal"]!;
+        normal.Font.Name = "Arial";
+        var sec = doc.AddSection();
+        var title = sec.AddParagraph("Rechnung Nr. RE-2026-0001");
+        title.Format.Font.Size = 14;
+        title.Format.Font.Bold = true;
+        sec.AddParagraph("Position 1: Beratungsleistung — 200,00 EUR netto");
+        sec.AddParagraph("Position 2: Entwicklung — 500,00 EUR netto");
+
+        var renderer = new PdfDocumentRenderer { Document = doc };
+        renderer.RenderDocument();
+        using var ms = new MemoryStream();
+        renderer.PdfDocument.Save(ms, closeStream: false);
+        return ms.ToArray();
+    }
+
+    // ── Stage 3 helper: a minimal but EN 16931-complete domestic invoice model ──
+    private static Invoice BuildValidInvoice(string number = "RE-2026-0001")
+    {
+        var seller = new TradeParty
+        {
+            Name = "Sebastian Fuchs Bad und Heizung GmbH & Co. KG",
+            Address = new PostalAddress
+            {
+                Line1 = "Germaniastraße 15",
+                City = "Düsseldorf",
+                PostalCode = "40223",
+                Country = CountryCode.Germany,
+            },
+            Contact = new TradeContact { Name = "Sebastian Fuchs", Email = "info@sanitaerfuchs.de", Telephone = "0211 3107222" },
+            ElectronicAddress = new Identifier("DE286366012", "0204"),
+        };
+        seller.TaxRegistrations.Add(new TaxRegistration("DE286366012", TaxRegistrationScheme.Vat));
+
+        var buyer = new TradeParty
+        {
+            Name = "Beispiel Kunde AG",
+            Address = new PostalAddress
+            {
+                Line1 = "Kundenweg 2",
+                City = "München",
+                PostalCode = "80331",
+                Country = CountryCode.Germany,
+            },
+        };
+
+        var invoice = new Invoice
+        {
+            InvoiceNumber = number,
+            IssueDate = new DateOnly(2026, 6, 1),
+            CurrencyCode = CurrencyCode.Eur,
+            BuyerReference = "04011000-12345-34",
+            Seller = seller,
+            Buyer = buyer,
+            Payment = new PaymentInstructions
+            {
+                MeansCode = PaymentMeansCode.SepaCreditTransfer,
+                RemittanceInformation = number,
+            },
+            PaymentTerms = new PaymentTerms
+            {
+                Description = "Zahlbar innerhalb von 14 Tagen netto.",
+                DueDate = new DateOnly(2026, 6, 15),
+            },
+        };
+        invoice.Payment.CreditTransfers.Add(new CreditTransferAccount
+        {
+            AccountId = "DE52301502000002091478",
+            AccountName = seller.Name,
+            BankId = "WELADED1KSD",
+        });
+        invoice.Lines.Add(new InvoiceLine
+        {
+            Id = "1",
+            Quantity = 1m,
+            UnitCode = UnitCode.One,
+            NetPrice = 200m,
+            VatCategory = VatCategoryCode.StandardRate,
+            VatRate = 19m,
+            Item = new TradeItem { Name = "Beratungsleistung", Description = "Beratung nach Aufwand" },
+        });
+        invoice.Lines.Add(new InvoiceLine
+        {
+            Id = "2",
+            Quantity = 1m,
+            UnitCode = UnitCode.One,
+            NetPrice = 500m,
+            VatCategory = VatCategoryCode.StandardRate,
+            VatRate = 19m,
+            Item = new TradeItem { Name = "Entwicklung", SellerItemId = "DEV-01" },
+        });
+
+        InvoiceCalculator.Recalculate(invoice);
+        return invoice;
+    }
+
+    // ── Stage 1 ───────────────────────────────────────────────────────────────
+    [Fact]
+    public void Stage1_PdfSharp_produces_a_valid_pdf()
+    {
+        byte[] pdf = BuildDummyPdfWithPdfSharp();
+
+        Assert.True(pdf.Length > 1000);
+        Assert.StartsWith("%PDF", Encoding.ASCII.GetString(pdf, 0, 4));
+    }
+
+    // ── Stage 2 (Spire rasterisation — the sprep preview path) ─────────────────
+    [Fact]
+    public async Task Stage2_Spire_rasterises_the_pdf_to_preview_images()
+    {
+        FuchsPdf.SetLicense();
+        byte[] pdf = BuildDummyPdfWithPdfSharp();
+
+        var images = await FuchsPdf.BytesToImageCollection(pdf);
+
+        Assert.True(images.TotalPages >= 1);
+        Assert.NotEmpty(images.ImgB64Array);
+        Assert.All(images.ImgB64Array, b64 => Assert.False(string.IsNullOrWhiteSpace(b64)));
+    }
+
+    // ── Stage 3 (eRechnung XML) ────────────────────────────────────────────────
+    [Theory]
+    [InlineData(XRechnungSyntax.Ubl)]
+    [InlineData(XRechnungSyntax.Cii)]
+    public void Stage3_eRechnung_XRechnung_is_valid(XRechnungSyntax syntax)
+    {
+        var result = EInvoice.CreateInvoice(BuildValidInvoice())
+            .ToXRechnung(syntax, XRechnungVersion.V4_0);
+
+        Assert.True(result.Success);
+        Assert.True(result.Validation.IsValid, result.Validation.ToString());
+        Assert.Contains("RE-2026-0001", Encoding.UTF8.GetString(result.Value!));
+    }
+
+    // ── Stage 3 (ZUGFeRD hybrid embedded into the PdfSharp visual PDF) ─────────
+    [Fact]
+    public void Stage3_eRechnung_Zugferd_embeds_xml_into_supplied_visual_pdf()
+    {
+        byte[] visualPdf = BuildDummyPdfWithPdfSharp();
+
+        var result = EInvoice.CreateInvoice(BuildValidInvoice())
+            .ToZugferd(ZugferdProfile.EN16931, visualPdf);
+
+        Assert.True(result.Success);
+        Assert.StartsWith("%PDF", Encoding.ASCII.GetString(result.Value!, 0, 4));
+
+        using var ms = new MemoryStream(result.Value!);
+        var pdfDoc = PdfReader.Open(ms, PdfDocumentOpenMode.Import);
+        // Factur-X associated-file array must be present on the catalog.
+        Assert.NotNull(pdfDoc.Internals.Catalog.Elements.GetArray("/AF"));
+    }
+
+    // ── Full chain: PdfSharp → Spire images → eRechnung hybrid ─────────────────
+    [Fact]
+    public async Task FullChain_pdfsharp_spire_eRechnung()
+    {
+        FuchsPdf.SetLicense();
+
+        // 1. Visual PDF via PdfSharp.
+        byte[] visualPdf = BuildDummyPdfWithPdfSharp();
+        Assert.StartsWith("%PDF", Encoding.ASCII.GetString(visualPdf, 0, 4));
+
+        // 2. Preview images via Spire.
+        var images = await FuchsPdf.BytesToImageCollection(visualPdf);
+        Assert.True(images.TotalPages >= 1);
+        Assert.NotEmpty(images.ImgB64Array);
+
+        // 3. eRechnung (ZUGFeRD/Factur-X) embedding the CII XML into the visual PDF.
+        var hybrid = EInvoice.CreateInvoice(BuildValidInvoice()).ToZugferd(ZugferdProfile.EN16931, visualPdf);
+        Assert.True(hybrid.Success);
+        Assert.True(hybrid.Validation.IsValid, hybrid.Validation.ToString());
+
+        using var ms = new MemoryStream(hybrid.Value!);
+        var pdfDoc = PdfReader.Open(ms, PdfDocumentOpenMode.Import);
+        var names = pdfDoc.Internals.Catalog.Elements.GetDictionary("/Names");
+        var embeddedFiles = names!.Elements.GetDictionary("/EmbeddedFiles");
+        var nameArray = embeddedFiles!.Elements.GetArray("/Names");
+        Assert.Contains(nameArray!.Elements, e => e.ToString()!.Contains("factur-x.xml"));
+    }
+
+    // ── Intentionally failing conversion path ──────────────────────────────────
+    [Fact]
+    public void eRechnung_strict_validation_withholds_output_on_invalid_invoice()
+    {
+        var invoice = BuildValidInvoice("RE-2026-0009");
+        invoice.BuyerReference = null; // violates BR-DE-15 for XRechnung
+
+        var result = EInvoice.CreateInvoice(invoice)
+            .ToXRechnung(XRechnungSyntax.Ubl, XRechnungVersion.V4_0,
+                new ConversionOptions { StrictValidation = true });
+
+        Assert.False(result.Success);
+        Assert.Null(result.Value);
+        Assert.Contains(result.Validation.Errors, m => m.RuleId == "BR-DE-15");
+    }
+
+    // ── Spire license selection (managed secret vs embedded fallback) ──────────
+    [Theory]
+    [InlineData(null)]
+    [InlineData("")]
+    [InlineData("   ")]
+    public void ResolveLicenseKey_falls_back_to_embedded_when_secret_absent(string? provided)
+    {
+        string key = FuchsPdf.ResolveLicenseKey(provided);
+
+        Assert.False(string.IsNullOrWhiteSpace(key));
+        Assert.True(key.Length > 100); // the embedded key, not the (empty) input
+    }
+
+    [Fact]
+    public void ResolveLicenseKey_uses_managed_secret_when_present()
+    {
+        const string secret = "MANAGED-SECRET-LICENSE-VALUE";
+
+        Assert.Equal(secret, FuchsPdf.ResolveLicenseKey(secret));
+    }
+
+    [Fact]
+    public void LicenseConfigKey_matches_the_managed_secret_name_in_appsettings()
+    {
+        // The Key Vault secret is "fuchs--SpirePdf-License"; the secret-management layer strips
+        // the app prefix, splits "--" into ":" and maps "-" to "_" per segment. So the managed
+        // key "SpirePdf-License" must surface under the config key the service reads.
+        const string managedSecretName = "SpirePdf-License";
+        string expectedConfigKey = string.Join(':',
+            managedSecretName.Split("--").Select(seg => seg.Replace("-", "_")));
+
+        Assert.Equal(FuchsPdfService.LicenseConfigKey, expectedConfigKey);
+
+        // And that managed secret is actually registered in the real appsettings.json.
+        var config = new ConfigurationBuilder()
+            .SetBasePath(AppContext.BaseDirectory)
+            .AddJsonFile("appsettings.json", optional: false)
+            .Build();
+        var managedKeys = config.GetSection("SecretManagement:ManagedSecretKeys").Get<string[]>() ?? [];
+        Assert.Contains(managedSecretName, managedKeys);
+    }
+
+    [Theory]
+    [InlineData("SpirePdf_License")]   // managed-secret mapping (fuchs--SpirePdf-License → '-' to '_')
+    [InlineData("SpirePdf-License")]   // verbatim, e.g. appsettings.Development.json
+    [InlineData("SpirePdf:License")]   // ':'-hierarchy variant
+    [InlineData("fuchs:SpirePdf-License")]
+    public void ResolveLicenseFromConfiguration_FindsLicenseUnderEachKnownKeyVariant(string key)
+    {
+        var config = new ConfigurationBuilder()
+            .AddInMemoryCollection(new Dictionary<string, string?> { [key] = "the-license-value" })
+            .Build();
+
+        string? value = FuchsPdfService.ResolveLicenseFromConfiguration(config, out string? matchedKey);
+
+        Assert.Equal("the-license-value", value);
+        Assert.Equal(key, matchedKey);
+    }
+
+    [Fact]
+    public void ResolveLicenseFromConfiguration_ReturnsNull_WhenNoCandidateHasAValue()
+    {
+        var config = new ConfigurationBuilder()
+            .AddInMemoryCollection(new Dictionary<string, string?>
+            {
+                ["SpirePdf_License"] = "   ",              // whitespace-only is treated as absent
+                ["Unrelated:Key"]    = "x"
+            })
+            .Build();
+
+        string? value = FuchsPdfService.ResolveLicenseFromConfiguration(config, out string? matchedKey);
+
+        Assert.Null(value);
+        Assert.Null(matchedKey);
+    }
+
+    [Fact]
+    public void ResolveLicenseFromConfiguration_ReturnsNull_WhenValueIsUnloadedManagedSecretPlaceholder()
+    {
+        // appsettings.json ships "SpirePdf_License": "MANAGED_BY_KEYVAULT" so the key always
+        // exists; until Key Vault/cache overrides it, the literal must be treated as "no license"
+        // so the embedded fallback is used rather than applying the placeholder as a bogus key.
+        var config = new ConfigurationBuilder()
+            .AddInMemoryCollection(new Dictionary<string, string?>
+            {
+                [FuchsPdfService.LicenseConfigKey] = FuchsPdfService.UnloadedSecretPlaceholder
+            })
+            .Build();
+
+        string? value = FuchsPdfService.ResolveLicenseFromConfiguration(config, out string? matchedKey);
+
+        Assert.Null(value);
+        Assert.Null(matchedKey);
+    }
+
+    [Fact]
+    public void ResolveLicenseFromConfiguration_SkipsPlaceholder_AndReturnsRealValueFromAnotherCandidate()
+    {
+        // The canonical key still carries the unresolved placeholder while a real license was
+        // supplied verbatim (e.g. appsettings.Development.json) under a different candidate key.
+        var config = new ConfigurationBuilder()
+            .AddInMemoryCollection(new Dictionary<string, string?>
+            {
+                [FuchsPdfService.LicenseConfigKey] = FuchsPdfService.UnloadedSecretPlaceholder,
+                ["SpirePdf-License"]               = "the-real-license"
+            })
+            .Build();
+
+        string? value = FuchsPdfService.ResolveLicenseFromConfiguration(config, out string? matchedKey);
+
+        Assert.Equal("the-real-license", value);
+        Assert.Equal("SpirePdf-License", matchedKey);
+    }
+
+    [Fact]
+    public void SpireLikeConfigKeys_ReportsSpireRelatedKeysForDiagnostics()
+    {
+        var config = new ConfigurationBuilder()
+            .AddInMemoryCollection(new Dictionary<string, string?>
+            {
+                ["fuchs:SpirePdf-License"] = "value",
+                ["Other:Setting"]          = "value"
+            })
+            .Build();
+
+        var keys = FuchsPdfService.SpireLikeConfigKeys(config).ToArray();
+
+        Assert.Contains("fuchs:SpirePdf-License", keys);
+        Assert.DoesNotContain("Other:Setting", keys);
+    }
+}

Fuchs.Tests/ProcessWebComServiceTests.cs

@@ -2,6 +2,7 @@
 using System.Collections.Generic;
 using System.Diagnostics.Metrics;
 using System.IO;
+using System.Linq;
 using System.Net;
 using System.Net.Http;
 using System.Threading;
@@ -48,6 +49,12 @@ public class ProcessWebComServiceTests
         }
     }
 
+    private sealed class ThrowingHandler : HttpMessageHandler
+    {
+        protected override Task<HttpResponseMessage> SendAsync(HttpRequestMessage request, CancellationToken cancellationToken)
+            => throw new HttpRequestException("simulated transport failure");
+    }
+
     private sealed class StubHttpClientFactory : IHttpClientFactory
     {
         private readonly HttpMessageHandler _handler;
@@ -55,6 +62,41 @@ public class ProcessWebComServiceTests
         public HttpClient CreateClient(string name) => new(_handler, disposeHandler: false);
     }
 
+    /// <summary>
+    /// Captures what would be written to <c>fds__logEmail</c> without hitting a database, by
+    /// overriding the audit-log write. Lets tests assert that every send path is logged and that
+    /// failures carry the service response / exception detail.
+    /// </summary>
+    private sealed class CapturingComService : ProcessWebComService
+    {
+        public readonly List<(bool success, List<string> log)> Entries = new();
+
+        public CapturingComService(
+            IOptions<ProcessWebComSettings> settings,
+            IOptions<FuchsEmailSettings> emailSettings,
+            IHttpClientFactory httpClientFactory)
+            : base(NullLogger<ProcessWebComService>.Instance, intranet: null!, settings, emailSettings, httpClientFactory)
+        {
+        }
+
+        protected override Task WriteAuditLogAsync(string reference, string guid, string config,
+            DateTime sent, bool success, IEnumerable<string> errors)
+        {
+            Entries.Add((success, errors.ToList()));
+            return Task.CompletedTask;
+        }
+    }
+
+    private static CapturingComService CreateCapturing(HttpMessageHandler handler, bool enabled = true, string? overrideRecipient = null)
+    {
+        var settings = Options.Create(new ProcessWebComSettings
+        {
+            Enabled = enabled, BaseUrl = "https://mailer.test", AccountId = "acct", Token = "tok"
+        });
+        var emailSettings = Options.Create(new FuchsEmailSettings { OverrideRecipient = overrideRecipient });
+        return new CapturingComService(settings, emailSettings, new StubHttpClientFactory(handler));
+    }
+
     private static ProcessWebComService CreateService(StubHandler handler, bool enabled = true, string? overrideRecipient = null)
     {
         var settings = Options.Create(new ProcessWebComSettings
@@ -129,6 +171,102 @@ public class ProcessWebComServiceTests
         Assert.Equal(0, handler.CallCount);
     }
 
+    // ── Audit logging: every attempt is logged; failures carry the service response ─
+    [Fact]
+    public async Task SendEmailAsync_Success_LogsSuccessfulAttempt()
+    {
+        var svc = CreateCapturing(new StubHandler(HttpStatusCode.OK));
+
+        await svc.SendEmailAsync("inv_log_ok", "S", "<p>x</p>", "kunde@example.de", "Kunde");
+
+        var entry = Assert.Single(svc.Entries);
+        Assert.True(entry.success);
+    }
+
+    [Fact]
+    public async Task SendEmailAsync_ApiError_LogsFailureIncludingServiceResponse()
+    {
+        var svc = CreateCapturing(new StubHandler(HttpStatusCode.InternalServerError, "mailer rejected: quota exceeded"));
+
+        bool result = await svc.SendEmailAsync("inv_log_api", "S", "<p>x</p>", "kunde@example.de", "Kunde");
+
+        Assert.False(result);
+        var entry = Assert.Single(svc.Entries);
+        Assert.False(entry.success);
+        Assert.Contains(entry.log, l => l.Contains("mailer rejected: quota exceeded"));  // raw service response
+        Assert.Contains(entry.log, l => l.Contains("500"));                               // HTTP status
+    }
+
+    [Fact]
+    public async Task SendEmailAsync_TransportException_LogsFailureIncludingExceptionDetail()
+    {
+        var svc = CreateCapturing(new ThrowingHandler());
+
+        bool result = await svc.SendEmailAsync("inv_log_ex", "S", "<p>x</p>", "kunde@example.de", "Kunde");
+
+        Assert.False(result);
+        var entry = Assert.Single(svc.Entries);
+        Assert.False(entry.success);
+        Assert.Contains(entry.log, l => l.Contains("Exception while sending"));
+        Assert.Contains(entry.log, l => l.Contains("simulated transport failure"));
+    }
+
+    [Theory]
+    [InlineData("not-an-email")]
+    [InlineData("")]
+    public async Task SendEmailAsync_InvalidEmail_StillLogsFailedAttempt(string badEmail)
+    {
+        var svc = CreateCapturing(new StubHandler(HttpStatusCode.OK));
+
+        bool result = await svc.SendEmailAsync("inv_log_bad", "S", "<p>x</p>", badEmail, "Kunde");
+
+        Assert.False(result);
+        var entry = Assert.Single(svc.Entries);
+        Assert.False(entry.success);
+        Assert.Contains(entry.log, l => l.Contains("Invalid recipient email address"));
+    }
+
+    [Fact]
+    public async Task SendEmailAsync_Disabled_LogsFailedAttempt()
+    {
+        var svc = CreateCapturing(new StubHandler(HttpStatusCode.OK), enabled: false);
+
+        await svc.SendEmailAsync("inv_log_dis", "S", "<p>x</p>", "kunde@example.de", "Kunde");
+
+        var entry = Assert.Single(svc.Entries);
+        Assert.False(entry.success);
+        Assert.Contains(entry.log, l => l.ToLowerInvariant().Contains("disabled"));
+    }
+
+    // ── Audit-log parameters honour the NOT NULL columns of fds__emaillog ──────
+    [Fact]
+    public void BuildAuditLogParameters_FailedAttempt_NeverPassesNullForNotNullColumns()
+    {
+        // fds__emaillog.config and .DateSent are NOT NULL; a failed/unset send must not send NULL
+        // (regression: it previously did, so every audit write failed and no email was ever logged).
+        var pl = ProcessWebComService.BuildAuditLogParameters(
+            "admin_test", guid: "", config: "", sent: default, success: false, errors: new[] { "err" });
+
+        object? config = pl.Single(p => p.ParameterName == "@config").Value;
+        object? dateSent = pl.Single(p => p.ParameterName == "@DateSent").Value;
+
+        Assert.Equal("", config);
+        Assert.NotEqual(DBNull.Value, config);
+        Assert.IsType<DateTime>(dateSent);
+        Assert.NotEqual((object)DBNull.Value, dateSent);
+    }
+
+    [Fact]
+    public void BuildAuditLogParameters_SuccessfulSend_KeepsProvidedSentTimestamp()
+    {
+        var when = new DateTime(2026, 7, 16, 12, 0, 0, DateTimeKind.Utc);
+
+        var pl = ProcessWebComService.BuildAuditLogParameters(
+            "inv_1", guid: "g1", config: "", sent: when, success: true, errors: Array.Empty<string>());
+
+        Assert.Equal(when, pl.Single(p => p.ParameterName == "@DateSent").Value);
+    }
+
     // ── Dev/test recipient override safety net ─────────────────────────────────
     [Fact]
     public async Task SendEmailAsync_OverrideRecipientSet_RedirectsToOverrideAddress()
@@ -141,7 +279,7 @@ public class ProcessWebComServiceTests
         Assert.True(result);
         Assert.Equal(1, handler.CallCount);
         var json = JObject.Parse(handler.LastRequestBody!);
-        Assert.Equal("dev-inbox@example.test", json["recipient"]!.ToString());
+        Assert.Equal("dev-inbox@example.test", json["communication"]!["to"]!.ToString());
     }
 
     [Fact]
@@ -153,7 +291,7 @@ public class ProcessWebComServiceTests
         await svc.SendEmailAsync("inv_ov2", "Rechnung 123", "<p>hi</p>", "realcustomer@example.de", "Kunde");
 
         var json = JObject.Parse(handler.LastRequestBody!);
-        string subject = json["subject"]!.ToString();
+        string subject = json["communication"]!["subject"]!.ToString();
         Assert.Contains("realcustomer@example.de", subject);
         Assert.Contains("Rechnung 123", subject);
     }
@@ -169,7 +307,7 @@ public class ProcessWebComServiceTests
         Assert.True(result);
         Assert.Equal(1, handler.CallCount);
         var json = JObject.Parse(handler.LastRequestBody!);
-        Assert.Equal("dev-inbox@example.test", json["recipient"]!.ToString());
+        Assert.Equal("dev-inbox@example.test", json["communication"]!["to"]!.ToString());
     }
 
     [Fact]
@@ -181,7 +319,7 @@ public class ProcessWebComServiceTests
         await svc.SendEmailAsync("inv_ov4", "Subject", "<p>hi</p>", "realcustomer@example.de", "Kunde");
 
         var json = JObject.Parse(handler.LastRequestBody!);
-        Assert.Equal("realcustomer@example.de", json["recipient"]!.ToString());
+        Assert.Equal("realcustomer@example.de", json["communication"]!["to"]!.ToString());
     }
 
     // ── Override enforcement across every real appsettings*.json environment ───
@@ -194,9 +332,9 @@ public class ProcessWebComServiceTests
     // hand-typed literal - so a future edit that silently breaks the override key
     // or its value in any appsettings*.json file would fail this test.
     //
-    // Note: this API has a single "recipient" field - there is no distinct
+    // Note: this API has a single "communication.to" field - there is no distinct
     // to/cc/bcc concept anywhere in the codebase (see ProcessWebComService.
-    // SendEmailAsync / payload.recipient). "to/cc/bcc cleared" is therefore fully
+    // SendEmailAsync / communication.to). "to/cc/bcc cleared" is therefore fully
     // satisfied by asserting that field no longer carries the original recipient
     // once an override is configured.
     public static IEnumerable<object[]> AppSettingsEnvironments()
@@ -236,7 +374,7 @@ public class ProcessWebComServiceTests
         Assert.True(result);
         Assert.Equal(1, handler.CallCount);
         var json = JObject.Parse(handler.LastRequestBody!);
-        string sentRecipient = json["recipient"]!.ToString();
+        string sentRecipient = json["communication"]!["to"]!.ToString();
 
         if (!string.IsNullOrWhiteSpace(overrideRecipient))
         {
@@ -266,7 +404,7 @@ public class ProcessWebComServiceTests
         Assert.True(result);
         Assert.NotNull(handler.LastRequestBody);
         var json = JObject.Parse(handler.LastRequestBody!);
-        var att = (JArray)json["attachments"]!;
+        var att = (JArray)json["communication"]!["attachments"]!;
         Assert.Single(att);
         Assert.Equal("Rechnung.pdf",        att[0]!["filename"]!.ToString());
         Assert.Equal("application/pdf",      att[0]!["mimeType"]!.ToString());

Fuchs.Tests/ReminderDraftCalculatorTests.cs

@@ -0,0 +1,92 @@
+using Fuchs.intranet;
+using Newtonsoft.Json.Linq;
+using Xunit;
+
+namespace Fuchs.Tests;
+
+/// <summary>
+/// Exhaustively exercises the pure reminder-draft aggregation/validation (ADR 0006,
+/// the reminder mirror of <see cref="InvoiceDraftCalculatorTests"/>). Being static/pure,
+/// the open-amount math and the plausibility checks are unit-testable without a DB.
+/// </summary>
+public class ReminderDraftCalculatorTests
+{
+    private static ReminderDraftSession Session(string newJson) =>
+        new() { New = JObject.Parse(newJson) };
+
+    [Theory]
+    [InlineData("{'amount':119,'amount_payed':0}", 119, 0, 119)]
+    [InlineData("{'amount':119,'amount_payed':20}", 119, 20, 99)]
+    [InlineData("{'amount':'119,50','amount_payed':'19,50'}", 119.50, 19.50, 100)]   // German decimals
+    [InlineData("{'amount':'100.00','amount_payed':'40.00'}", 100, 40, 60)]          // invariant decimals
+    [InlineData("{}", 0, 0, 0)]                                                       // missing → 0
+    [InlineData("{'amount':50,'amount_payed':80}", 50, 80, -30)]                      // overpaid → negative
+    public void RecomputeTotals_ComputesOpenAmount(string newJson, double total, double payed, double open)
+    {
+        var s = Session(newJson);
+        ReminderDraftCalculator.RecomputeTotals(s);
+        Assert.Equal((decimal)total, s.Sums.AmountTotal);
+        Assert.Equal((decimal)payed, s.Sums.AmountPayed);
+        Assert.Equal((decimal)open,  s.Sums.AmountOpen);
+    }
+
+    [Fact]
+    public void Validate_EmptyEmail_Warns()
+    {
+        var s = Session("{'amount':119,'invoiceaddress':'Weg 1','subject':'X'}");
+        ReminderDraftCalculator.RecomputeTotals(s);
+        ReminderDraftCalculator.Validate(s);
+        Assert.Contains(s.ValidationMessages, m => m.Field == "email" && m.Severity == "warning");
+    }
+
+    [Theory]
+    [InlineData("bad")]
+    [InlineData("no-at-sign.de")]
+    [InlineData("trailing@dot.")]
+    public void Validate_InvalidEmail_Errors(string email)
+    {
+        var s = Session($"{{'amount':119,'invoiceemail':'{email}','invoiceaddress':'Weg 1','subject':'X'}}");
+        ReminderDraftCalculator.RecomputeTotals(s);
+        ReminderDraftCalculator.Validate(s);
+        Assert.Contains(s.ValidationMessages, m => m.Field == "email" && m.Severity == "error");
+    }
+
+    [Fact]
+    public void Validate_ValidEmail_NoEmailMessage()
+    {
+        var s = Session("{'amount':119,'invoiceemail':'a@b.de','invoiceaddress':'Weg 1','subject':'X'}");
+        ReminderDraftCalculator.RecomputeTotals(s);
+        ReminderDraftCalculator.Validate(s);
+        Assert.DoesNotContain(s.ValidationMessages, m => m.Field == "email");
+    }
+
+    [Fact]
+    public void Validate_EmptyAddressAndSubject_Warn()
+    {
+        var s = Session("{'amount':119,'invoiceemail':'a@b.de'}");
+        ReminderDraftCalculator.RecomputeTotals(s);
+        ReminderDraftCalculator.Validate(s);
+        Assert.Contains(s.ValidationMessages, m => m.Field == "address" && m.Severity == "warning");
+        Assert.Contains(s.ValidationMessages, m => m.Field == "subject" && m.Severity == "warning");
+    }
+
+    [Theory]
+    [InlineData("{'amount':0,'amount_payed':0,'invoiceemail':'a@b.de','invoiceaddress':'W','subject':'X'}")]
+    [InlineData("{'amount':50,'amount_payed':80,'invoiceemail':'a@b.de','invoiceaddress':'W','subject':'X'}")]
+    public void Validate_NonPositiveOpenAmount_Warns(string newJson)
+    {
+        var s = Session(newJson);
+        ReminderDraftCalculator.RecomputeTotals(s);
+        ReminderDraftCalculator.Validate(s);
+        Assert.Contains(s.ValidationMessages, m => m.Field == "amount" && m.Severity == "warning");
+    }
+
+    [Fact]
+    public void Validate_HealthyDraft_HasNoMessages()
+    {
+        var s = Session("{'amount':119,'amount_payed':0,'invoiceemail':'a@b.de','invoiceaddress':'Weg 1','subject':'Zahlungserinnerung'}");
+        ReminderDraftCalculator.RecomputeTotals(s);
+        ReminderDraftCalculator.Validate(s);
+        Assert.Empty(s.ValidationMessages);
+    }
+}

Fuchs.Tests/ReminderDraftServiceTests.cs

@@ -0,0 +1,307 @@
+using System;
+using System.Linq;
+using System.Threading.Tasks;
+using Fuchs.intranet;
+using Fuchs.Services;
+using Microsoft.Extensions.Configuration;
+using Microsoft.Extensions.Logging.Abstractions;
+using MigraDoc.DocumentObjectModel;
+using Newtonsoft.Json.Linq;
+using OCORE.security;
+using Xunit;
+using static OCORE.OCORE_dictionaries;
+
+namespace Fuchs.Tests;
+
+/// <summary>
+/// Exercises the reminder draft edit orchestrator's pure paths (open/patch/history/flush)
+/// without a database — the reminder mirror of <see cref="InvoiceDraftServiceTests"/>,
+/// proving the backend-authoritative model behaves correctly at the service seam (ADR 0006).
+/// </summary>
+public class ReminderDraftServiceTests
+{
+    /// <summary>Captures the reminder handed to registration and returns it with a fake DB id — no SQL.</summary>
+    private sealed class FakeReminderService : IReminderService
+    {
+        public FdsReminderData? Registered;
+        public bool? LastChange;
+        public FdsReminderData? PreviewReminder;
+        public bool? PreviewDraft;
+
+        public Task<FdsReminderData> RegisterReminderAsync(FdsReminderData reminder, bool change, string remId, string userAccountId, DatabaseSecurity dbSec)
+        {
+            Registered = reminder;
+            LastChange = change;
+            reminder.ReminderRegistration = new GenericObjectDictionary(new System.Collections.Generic.Dictionary<string, object> { ["Id"] = "REM42" });
+            return Task.FromResult(reminder);
+        }
+        public Document GenerateReminderPdf(FdsReminderData reminder, bool draft) { PreviewReminder = reminder; PreviewDraft = draft; return new Document(); }
+        public Task<FdsReminderData> LoadReminderAsync(string id, string u, DatabaseSecurity s) => throw new NotSupportedException();
+        public Task<byte[]> RenderReminderPdfBytesAsync(FdsReminderData r, bool d) => throw new NotSupportedException();
+        public Task<byte[]> StoreReminderDocumentFileAsync(FdsReminderData r, bool d, string u, DatabaseSecurity s) => throw new NotSupportedException();
+        public Task<byte[]> GetReminderFileAsync(FdsReminderData r, bool d, fds.IFdsMfr m, string u, DatabaseSecurity s) => throw new NotSupportedException();
+        public Task<(System.IO.FileInfo? file, byte[]? content)> GetStoredFileAsync(string id, string u, DatabaseSecurity s) => throw new NotSupportedException();
+    }
+
+    private static (ReminderDraftEditService svc, FakeReminderService rem) NewService()
+    {
+        var cache = new ReminderDraftCache(new ConfigurationBuilder().Build());
+        var rem = new FakeReminderService();
+        var svc = new ReminderDraftEditService(cache, rem, NullLogger<ReminderDraftEditService>.Instance);
+        return (svc, rem);
+    }
+
+    private static JObject Payload() => JObject.Parse(@"{
+        'rem':{'invid':'INV5','type':'R','invoiceid':'R2026-1','invoicedate':'2026-06-01'},
+        'new':{'invoiceemail':'a@b.de','invoiceaddress':'Weg 1','subject':'Zahlungserinnerung','amount':119,'amount_payed':0}
+    }");
+
+    [Fact]
+    public void OpenFromPayload_SeedsSessionAndComputesOpenAmount()
+    {
+        var (svc, _) = NewService();
+        var s = svc.OpenFromPayload(Payload(), "user1");
+        Assert.False(string.IsNullOrEmpty(s.Token));
+        Assert.Equal(0, s.Version);
+        Assert.Equal(119m, s.Sums.AmountTotal);
+        Assert.Equal(119m, s.Sums.AmountOpen);
+    }
+
+    [Fact]
+    public void ApplyPatch_Email_MutatesBumpsVersionAndRecordsHistory()
+    {
+        var (svc, _) = NewService();
+        var s = svc.OpenFromPayload(Payload(), "user1");
+
+        var s2 = svc.ApplyPatch(s.Token, new ReminderDraftDelta { Target = "email", Value = JToken.FromObject("neu@x.de") });
+
+        Assert.NotNull(s2);
+        Assert.Equal(1, s2!.Version);
+        Assert.Equal("neu@x.de", s2.New["invoiceemail"]!.Value<string>());
+        var h = Assert.Single(s2.History);
+        Assert.Equal("email", h.Target);
+        Assert.Equal("a@b.de", h.OldValue);
+        Assert.Equal("neu@x.de", h.NewValue);
+    }
+
+    [Fact]
+    public void ApplyPatch_Amount_RecomputesOpenAmount()
+    {
+        var (svc, _) = NewService();
+        var s = svc.OpenFromPayload(Payload(), "user1");
+
+        var s2 = svc.ApplyPatch(s.Token, new ReminderDraftDelta { Target = "amount", Value = JToken.FromObject(200) });
+
+        Assert.Equal(200m, s2!.Sums.AmountTotal);
+        Assert.Equal(200m, s2.Sums.AmountOpen);
+    }
+
+    [Fact]
+    public void ApplyPatch_AmountPayed_RecomputesOpenAmount()
+    {
+        var (svc, _) = NewService();
+        var s = svc.OpenFromPayload(Payload(), "user1");
+
+        var s2 = svc.ApplyPatch(s.Token, new ReminderDraftDelta { Target = "amount_payed", Value = JToken.FromObject(19) });
+
+        Assert.Equal(100m, s2!.Sums.AmountOpen);   // 119 - 19
+    }
+
+    [Fact]
+    public void ApplyPatch_AmountFromGermanString_NormalisesToInvariant()
+    {
+        var (svc, _) = NewService();
+        var s = svc.OpenFromPayload(Payload(), "user1");
+
+        var s2 = svc.ApplyPatch(s.Token, new ReminderDraftDelta { Target = "amount", Value = JToken.FromObject("249,90") });
+
+        Assert.Equal("249.90", s2!.New["amount"]!.Value<string>());   // stored invariant
+        Assert.Equal(249.90m, s2.Sums.AmountTotal);
+    }
+
+    [Fact]
+    public void ApplyPatch_UnknownToken_ReturnsNull()
+    {
+        var (svc, _) = NewService();
+        Assert.Null(svc.ApplyPatch("ghost", new ReminderDraftDelta { Target = "email", Value = JToken.FromObject("x@y.de") }));
+    }
+
+    [Fact]
+    public void ApplyPatch_UnknownTarget_IsNoOp()
+    {
+        var (svc, _) = NewService();
+        var s = svc.OpenFromPayload(Payload(), "user1");
+
+        var s2 = svc.ApplyPatch(s.Token, new ReminderDraftDelta { Target = "nonsense", Value = JToken.FromObject("x") });
+
+        Assert.Equal(0, s2!.Version);
+        Assert.Empty(s2.History);
+    }
+
+    [Theory]
+    [InlineData("subject", "subject")]
+    [InlineData("address", "invoiceaddress")]
+    [InlineData("text", "text")]
+    public void ApplyPatch_ScalarFieldDeltas_UpdateNew(string target, string newKey)
+    {
+        var (svc, _) = NewService();
+        var s = svc.OpenFromPayload(Payload(), "user1");
+
+        var s2 = svc.ApplyPatch(s.Token, new ReminderDraftDelta { Target = target, Value = JToken.FromObject("X-VALUE") });
+
+        Assert.Equal("X-VALUE", s2!.New[newKey]!.Value<string>());
+    }
+
+    [Theory]
+    [InlineData("subject", "subject")]
+    [InlineData("email", "invoiceemail")]
+    public void ApplyPatch_ScalarField_StripsHtmlWrapper(string target, string newKey)
+    {
+        var (svc, _) = NewService();
+        var s = svc.OpenFromPayload(Payload(), "user1");
+
+        var s2 = svc.ApplyPatch(s.Token, new ReminderDraftDelta { Target = target, Value = JToken.FromObject("<p>clean me</p>") });
+
+        Assert.Equal("clean me", s2!.New[newKey]!.Value<string>());
+        Assert.DoesNotContain("<", s2.New[newKey]!.Value<string>());
+    }
+
+    [Fact]
+    public void ApplyPatch_Address_MultilineHtml_KeepsLineBreaks()
+    {
+        var (svc, _) = NewService();
+        var s = svc.OpenFromPayload(Payload(), "user1");
+
+        var s2 = svc.ApplyPatch(s.Token, new ReminderDraftDelta
+        {
+            Target = "address",
+            Value = JToken.FromObject("<p>Firma AG</p><p>Weg 1<br>40000 Düsseldorf</p>")
+        });
+
+        Assert.Equal("Firma AG\nWeg 1\n40000 Düsseldorf", s2!.New["invoiceaddress"]!.Value<string>());
+    }
+
+    [Fact]
+    public void ApplyPatch_Contact_BuildsCustomValuesJson()
+    {
+        var (svc, _) = NewService();
+        var s = svc.OpenFromPayload(Payload(), "user1");
+
+        var s2 = svc.ApplyPatch(s.Token, new ReminderDraftDelta
+        {
+            Target = "contact",
+            Value = JObject.Parse(@"{'name':'Max Mustermann','email':'max@kunde.de'}")
+        });
+
+        var cv = JObject.Parse(s2!.New["CustomValues"]!.Value<string>()!);
+        Assert.Equal("Max Mustermann", cv["contactName"]!.Value<string>());
+        Assert.Equal("max@kunde.de", cv["contactEmail"]!.Value<string>());
+    }
+
+    [Fact]
+    public void ApplyPatch_MultipleEdits_AccumulateHistoryInOrder()
+    {
+        var (svc, _) = NewService();
+        var s = svc.OpenFromPayload(Payload(), "user1");
+
+        svc.ApplyPatch(s.Token, new ReminderDraftDelta { Target = "email", Value = JToken.FromObject("a1@x.de") });
+        svc.ApplyPatch(s.Token, new ReminderDraftDelta { Target = "subject", Value = JToken.FromObject("Mahnung 2") });
+        var s3 = svc.ApplyPatch(s.Token, new ReminderDraftDelta { Target = "amount", Value = JToken.FromObject(200) });
+
+        Assert.Equal(3, s3!.Version);
+        Assert.Equal(new[] { "email", "subject", "amount" }, s3.History.Select(h => h.Target).ToArray());
+        Assert.Equal(new[] { 1, 2, 3 }, s3.History.Select(h => h.Version).ToArray());
+    }
+
+    [Fact]
+    public void BuildState_ExposesPayloadSumsValidationAndVersion()
+    {
+        var (svc, _) = NewService();
+        var s = svc.OpenFromPayload(Payload(), "user1");
+        svc.ApplyPatch(s.Token, new ReminderDraftDelta { Target = "amount_payed", Value = JToken.FromObject(19) });
+
+        var state = JObject.FromObject(svc.BuildState(svc.Get(s.Token)!));
+
+        Assert.Equal(1, state["version"]!.Value<int>());
+        Assert.Equal(119m, state["sums"]!["amount_total"]!.Value<decimal>());
+        Assert.Equal(100m, state["sums"]!["amount_open"]!.Value<decimal>());
+        Assert.Equal(1, state["historyCount"]!.Value<int>());
+        Assert.NotNull(state["validation"]);
+    }
+
+    [Fact]
+    public async Task FlushToDbAsync_RegistersAndSetsRemId_CreatePath()
+    {
+        var (svc, rem) = NewService();
+        var s = svc.OpenFromPayload(Payload(), "user1");
+
+        var result = await svc.FlushToDbAsync(s.Token, "user1", null!);
+
+        Assert.NotNull(result);
+        Assert.Equal("REM42", result!.Id);
+        Assert.False(rem.LastChange);   // new draft (no prior RemId) → create
+        Assert.Equal("REM42", svc.Get(s.Token)!.RemId);
+        // the email/subject the editor set must reach registration
+        Assert.Equal("a@b.de", rem.Registered!.RawInvoiceEmail);
+        Assert.Equal("Zahlungserinnerung", rem.Registered!.NewValues!.getString("subject"));
+        Assert.Equal("INV5", rem.Registered!.RawInvId);
+    }
+
+    [Fact]
+    public async Task FlushToDbAsync_ExistingRemId_UpdatePath()
+    {
+        var (svc, rem) = NewService();
+        var payload = Payload();
+        payload["remid"] = "REM7";
+        var s = svc.OpenFromPayload(payload, "user1");
+
+        await svc.FlushToDbAsync(s.Token, "user1", null!);
+
+        Assert.True(rem.LastChange);   // prior RemId → update path
+    }
+
+    [Fact]
+    public void RenderPreview_SynthesizesDraftRegistrationFromSession()
+    {
+        var (svc, rem) = NewService();
+        var s = svc.OpenFromPayload(Payload(), "user1");
+
+        var doc = svc.RenderPreview(s.Token);
+
+        Assert.NotNull(doc);
+        Assert.True(rem.PreviewDraft);
+        Assert.True(rem.PreviewReminder!.IsDraft);
+        var reg = rem.PreviewReminder!.ReminderRegistration!;
+        Assert.Equal("Zahlungserinnerung", reg.getString("subject"));
+        Assert.Equal("Weg 1", reg.getString("SendToAddress"));
+        Assert.Equal("a@b.de", reg.getString("SendToEmail"));
+        Assert.Equal("R2026-1", reg.getString("InvoiceId"));
+        // the synthesised single-invoice row the reminder table renders
+        Assert.Single(rem.PreviewReminder!.ReminderItems);
+    }
+
+    [Fact]
+    public void RenderPreview_UnknownToken_ReturnsNull()
+    {
+        var (svc, _) = NewService();
+        Assert.Null(svc.RenderPreview("ghost"));
+    }
+
+    [Fact]
+    public void GetHistory_UnknownToken_IsEmpty()
+    {
+        var (svc, _) = NewService();
+        Assert.Empty(svc.GetHistory("ghost"));
+    }
+
+    [Fact]
+    public void Close_RemovesSession_ThenReportsFalse()
+    {
+        var (svc, _) = NewService();
+        var s = svc.OpenFromPayload(Payload(), "user1");
+
+        Assert.True(svc.Close(s.Token));
+        Assert.Null(svc.Get(s.Token));
+        Assert.False(svc.Close(s.Token));
+    }
+}

Fuchs.Tests/RequestValueHelperTests.cs

@@ -0,0 +1,93 @@
+using System.Collections.Generic;
+using Fuchs.Controllers;
+using Microsoft.AspNetCore.Http;
+using Microsoft.Extensions.Primitives;
+using Xunit;
+
+namespace Fuchs.Tests;
+
+/// <summary>
+/// Covers <see cref="RequestValueHelper.Resolve"/>, which backs IntranetController's
+/// Form()/HasForm() helpers. Endpoints in _allowedGet (e.g. req/idoc, rem/idoc) are invoked via
+/// a plain GET (window.open with '?id=...'), so this must resolve from the query string without
+/// ever touching an IFormCollection built from a non-form request (that would previously throw
+/// InvalidOperationException in production - see Do() unhandled-exception log for fn=req id=idoc).
+/// </summary>
+public class RequestValueHelperTests
+{
+    private static IFormCollection Form(params (string Key, string Value)[] pairs)
+    {
+        var dict = new Dictionary<string, StringValues>();
+        foreach (var (key, value) in pairs) dict[key] = value;
+        return new FormCollection(dict);
+    }
+
+    private static IQueryCollection Query(params (string Key, string Value)[] pairs)
+    {
+        var dict = new Dictionary<string, StringValues>();
+        foreach (var (key, value) in pairs) dict[key] = value;
+        return new QueryCollection(dict);
+    }
+
+    [Fact]
+    public void Resolve_FormContentTypeWithKey_ReturnsFormValue()
+    {
+        string? result = RequestValueHelper.Resolve(
+            hasFormContentType: true,
+            form: Form(("id", "abc123")),
+            query: Query(("id", "from-query")),
+            key: "id");
+
+        Assert.Equal("abc123", result);
+    }
+
+    [Fact]
+    public void Resolve_NoFormContentType_FallsBackToQuery()
+    {
+        // Simulates a GET request opened via window.open('?id=...'): no Content-Type header,
+        // so the (empty) form collection must not be consulted - only the query string.
+        string? result = RequestValueHelper.Resolve(
+            hasFormContentType: false,
+            form: FormCollection.Empty,
+            query: Query(("id", "7O32P")),
+            key: "id");
+
+        Assert.Equal("7O32P", result);
+    }
+
+    [Fact]
+    public void Resolve_FormContentTypeButKeyMissingFromForm_FallsBackToQuery()
+    {
+        string? result = RequestValueHelper.Resolve(
+            hasFormContentType: true,
+            form: Form(("other", "value")),
+            query: Query(("id", "7O32P")),
+            key: "id");
+
+        Assert.Equal("7O32P", result);
+    }
+
+    [Fact]
+    public void Resolve_KeyMissingFromBoth_ReturnsNull()
+    {
+        string? result = RequestValueHelper.Resolve(
+            hasFormContentType: true,
+            form: Form(("other", "value")),
+            query: Query(("other", "value")),
+            key: "id");
+
+        Assert.Null(result);
+    }
+
+    [Fact]
+    public void Resolve_NoFormContentTypeAndQueryEmpty_ReturnsNull()
+    {
+        string? result = RequestValueHelper.Resolve(
+            hasFormContentType: false,
+            form: FormCollection.Empty,
+            query: QueryCollection.Empty,
+            key: "id");
+
+        Assert.Null(result);
+    }
+}

Fuchs.Tests/StartupSelfTestServiceTests.cs

@@ -0,0 +1,357 @@
+using System;
+using System.Collections.Generic;
+using System.Threading;
+using System.Threading.Tasks;
+using Fuchs.intranet;
+using Fuchs.Services;
+using Microsoft.Extensions.Configuration;
+using Microsoft.Extensions.DependencyInjection;
+using Microsoft.Extensions.Logging.Abstractions;
+using Microsoft.Extensions.Options;
+using Xunit;
+
+namespace Fuchs.Tests;
+
+public class StartupSelfTestServiceTests
+{
+    private static StartupSelfTestSettings CreateSettings(
+        bool enabled,
+        bool checkKeyVault = true,
+        bool checkDatabase = true,
+        bool checkMfr = true,
+        bool sendStartupEmail = false,
+        string startupRecipient = "",
+        bool checkPdfLicense = false) => new()
+        {
+            Enabled = enabled,
+            CheckKeyVault = checkKeyVault,
+            CheckDatabase = checkDatabase,
+            CheckMfr = checkMfr,
+            CheckPdfLicense = checkPdfLicense,
+            SendStartupEmail = sendStartupEmail,
+            StartupEmailRecipient = startupRecipient,
+            StartupEmailRecipientName = "Monitor"
+        };
+
+    private static IConfiguration CreateConfiguration() =>
+        new ConfigurationBuilder().AddInMemoryCollection(new Dictionary<string, string?>
+        {
+            ["SecretManagement:AppName"] = "fuchs",
+            ["SecretManagement:ManagedSecretKeys:0"] = "Fuchs--Mailer--Token"
+        }).Build();
+
+    [Fact]
+    public async Task ExecuteAsync_Disabled_DoesNotRunAnyChecks()
+    {
+        using var service = new TestableStartupSelfTestService(
+            new ServiceCollection().BuildServiceProvider(),
+            CreateConfiguration(),
+            Options.Create(CreateSettings(enabled: false)),
+            NullLogger<StartupSelfTestService>.Instance)
+        {
+            KeyVaultResult = true,
+            DatabaseResult = true,
+            MfrResult = true,
+            MailerResult = true
+        };
+
+        await service.RunForTestAsync(CancellationToken.None);
+
+        Assert.Equal(0, service.KeyVaultCalls);
+        Assert.Equal(0, service.DatabaseCalls);
+        Assert.Equal(0, service.MfrCalls);
+        Assert.Equal(0, service.MailerCalls);
+    }
+
+    [Fact]
+    public async Task ExecuteAsync_EnabledWithAllChecks_CallsAllProbes()
+    {
+        using var service = new TestableStartupSelfTestService(
+            new ServiceCollection().BuildServiceProvider(),
+            CreateConfiguration(),
+            Options.Create(CreateSettings(enabled: true, checkKeyVault: true, checkDatabase: true, checkMfr: true, sendStartupEmail: true, startupRecipient: "ops@example.test", checkPdfLicense: true)),
+            NullLogger<StartupSelfTestService>.Instance)
+        {
+            KeyVaultResult = true,
+            DatabaseResult = true,
+            MfrResult = true,
+            MailerResult = true,
+            PdfLicenseResult = true
+        };
+
+        await service.RunForTestAsync(CancellationToken.None);
+
+        Assert.Equal(1, service.KeyVaultCalls);
+        Assert.Equal(1, service.DatabaseCalls);
+        Assert.Equal(1, service.MfrCalls);
+        Assert.Equal(1, service.MailerCalls);
+        Assert.Equal(1, service.PdfLicenseCalls);
+    }
+
+    [Fact]
+    public async Task ExecuteAsync_PdfLicenseCheckDisabled_DoesNotProbePdfLicense()
+    {
+        using var service = new TestableStartupSelfTestService(
+            new ServiceCollection().BuildServiceProvider(),
+            CreateConfiguration(),
+            Options.Create(CreateSettings(enabled: true, checkKeyVault: false, checkDatabase: false, checkMfr: false, checkPdfLicense: false)),
+            NullLogger<StartupSelfTestService>.Instance)
+        {
+            PdfLicenseResult = true
+        };
+
+        await service.RunForTestAsync(CancellationToken.None);
+
+        Assert.Equal(0, service.PdfLicenseCalls);
+    }
+
+    [Fact]
+    public async Task ProbePdfLicenseAsync_MissingLicenseString_ReturnsFalse()
+    {
+        var config = new ConfigurationBuilder()
+            .AddInMemoryCollection(new Dictionary<string, string?>())
+            .Build();
+        using var service = new ProbeExposingStartupSelfTestService(
+            new ServiceCollection().BuildServiceProvider(),
+            config,
+            Options.Create(CreateSettings(enabled: true, checkPdfLicense: true)),
+            NullLogger<StartupSelfTestService>.Instance);
+
+        bool ok = await service.InvokeProbePdfLicenseAsync(CancellationToken.None);
+
+        Assert.False(ok);
+    }
+
+    [Fact]
+    public async Task ProbePdfLicenseAsync_EmptyLicenseString_ReturnsFalse()
+    {
+        var config = new ConfigurationBuilder()
+            .AddInMemoryCollection(new Dictionary<string, string?>
+            {
+                [FuchsPdfService.LicenseConfigKey] = "   "
+            })
+            .Build();
+        using var service = new ProbeExposingStartupSelfTestService(
+            new ServiceCollection().BuildServiceProvider(),
+            config,
+            Options.Create(CreateSettings(enabled: true, checkPdfLicense: true)),
+            NullLogger<StartupSelfTestService>.Instance);
+
+        bool ok = await service.InvokeProbePdfLicenseAsync(CancellationToken.None);
+
+        Assert.False(ok);
+    }
+
+    [Fact]
+    public async Task ProbePdfLicenseAsync_InvalidLicenseString_ReportsUnlicensed()
+    {
+        // A syntactically-present but invalid key leaves Spire.PDF in evaluation mode, which the
+        // probe must detect (the evaluation watermark appears on the rendered document).
+        var config = new ConfigurationBuilder()
+            .AddInMemoryCollection(new Dictionary<string, string?>
+            {
+                [FuchsPdfService.LicenseConfigKey] = "not-a-valid-spire-license-key"
+            })
+            .Build();
+        using var service = new ProbeExposingStartupSelfTestService(
+            new ServiceCollection().BuildServiceProvider(),
+            config,
+            Options.Create(CreateSettings(enabled: true, checkPdfLicense: true)),
+            NullLogger<StartupSelfTestService>.Instance);
+
+        try
+        {
+            bool ok = await service.InvokeProbePdfLicenseAsync(CancellationToken.None);
+            Assert.False(ok);
+        }
+        finally
+        {
+            // Restore the embedded (valid-format) key so other Spire-using tests aren't left
+            // with a malformed license that makes Spire throw on save.
+            FuchsPdf.SetLicense();
+        }
+    }
+
+    [Fact]
+    public void SpirePdfIsLicensed_InEvaluationMode_ReturnsFalse()
+    {
+        // The embedded fallback key does not license current Spire.PDF, so Spire runs as the
+        // evaluation edition and stamps a watermark, which the detection reports as unlicensed.
+        FuchsPdf.SetLicense();
+
+        Assert.False(StartupSelfTestService.SpirePdfIsLicensed());
+    }
+
+    [Fact]
+    public async Task ExecuteAsync_EnabledWithMailerOnly_CallsOnlyMailerCheck()
+    {
+        using var service = new TestableStartupSelfTestService(
+            new ServiceCollection().BuildServiceProvider(),
+            CreateConfiguration(),
+            Options.Create(CreateSettings(enabled: true, checkKeyVault: false, checkDatabase: false, checkMfr: false, sendStartupEmail: true, startupRecipient: "ops@example.test")),
+            NullLogger<StartupSelfTestService>.Instance)
+        {
+            KeyVaultResult = true,
+            DatabaseResult = true,
+            MfrResult = true,
+            MailerResult = false
+        };
+
+        await service.RunForTestAsync(CancellationToken.None);
+
+        Assert.Equal(0, service.KeyVaultCalls);
+        Assert.Equal(0, service.DatabaseCalls);
+        Assert.Equal(0, service.MfrCalls);
+        Assert.Equal(1, service.MailerCalls);
+    }
+
+    [Fact]
+    public async Task RunOnce_Disabled_PublishesNotRunReport()
+    {
+        var reporter = new StartupCheckReporter();
+        using var service = new TestableStartupSelfTestService(
+            new ServiceCollection().BuildServiceProvider(),
+            CreateConfiguration(),
+            Options.Create(CreateSettings(enabled: false)),
+            NullLogger<StartupSelfTestService>.Instance,
+            reporter);
+
+        await service.RunForTestAsync(CancellationToken.None);
+
+        Assert.NotNull(reporter.Latest);
+        Assert.False(reporter.Latest!.Ran);
+    }
+
+    [Fact]
+    public async Task RunOnce_Enabled_PublishesReportWithPerCheckResults()
+    {
+        var reporter = new StartupCheckReporter();
+        using var service = new TestableStartupSelfTestService(
+            new ServiceCollection().BuildServiceProvider(),
+            CreateConfiguration(),
+            Options.Create(CreateSettings(enabled: true, checkKeyVault: true, checkDatabase: true, checkMfr: false, sendStartupEmail: true, startupRecipient: "ops@example.test", checkPdfLicense: false)),
+            NullLogger<StartupSelfTestService>.Instance,
+            reporter)
+        {
+            KeyVaultResult = true,
+            DatabaseResult = false,
+            MailerResult = true,
+        };
+
+        await service.RunForTestAsync(CancellationToken.None);
+
+        var report = reporter.Latest;
+        Assert.NotNull(report);
+        Assert.True(report!.Ran);
+        Assert.NotNull(report.CompletedUtc);
+        var kv = Assert.Single(report.Items, i => i.Name == "KeyVault");
+        Assert.True(kv.Enabled && kv.Ok);
+        var db = Assert.Single(report.Items, i => i.Name == "Database");
+        Assert.True(db.Enabled);
+        Assert.False(db.Ok);                       // intentionally-failing path
+        var mfr = Assert.Single(report.Items, i => i.Name == "MFR");
+        Assert.False(mfr.Enabled);                 // disabled check reported as not-enabled
+    }
+
+    [Fact]
+    public async Task ExecuteAsync_ProbeThrows_ServiceDoesNotThrowAndContinuesRemainingChecks()
+    {
+        using var service = new TestableStartupSelfTestService(
+            new ServiceCollection().BuildServiceProvider(),
+            CreateConfiguration(),
+            Options.Create(CreateSettings(enabled: true, checkKeyVault: true, checkDatabase: true, checkMfr: true, sendStartupEmail: true, startupRecipient: "ops@example.test")),
+            NullLogger<StartupSelfTestService>.Instance)
+        {
+            KeyVaultException = new InvalidOperationException("probe failed"),
+            DatabaseResult = true,
+            MfrResult = true,
+            MailerResult = true
+        };
+
+        var exception = await Record.ExceptionAsync(async () =>
+        {
+            await service.RunForTestAsync(CancellationToken.None);
+        });
+
+        Assert.Null(exception);
+        Assert.Equal(1, service.KeyVaultCalls);
+        Assert.Equal(1, service.DatabaseCalls);
+        Assert.Equal(1, service.MfrCalls);
+        Assert.Equal(1, service.MailerCalls);
+    }
+
+    private sealed class TestableStartupSelfTestService : StartupSelfTestService
+    {
+        public int KeyVaultCalls { get; private set; }
+        public int DatabaseCalls { get; private set; }
+        public int MfrCalls { get; private set; }
+        public int MailerCalls { get; private set; }
+        public int PdfLicenseCalls { get; private set; }
+        public bool KeyVaultResult { get; set; }
+        public bool DatabaseResult { get; set; }
+        public bool MfrResult { get; set; }
+        public bool MailerResult { get; set; }
+        public bool PdfLicenseResult { get; set; }
+        public Exception? KeyVaultException { get; set; }
+
+        public TestableStartupSelfTestService(
+            IServiceProvider serviceProvider,
+            IConfiguration configuration,
+            IOptions<StartupSelfTestSettings> settings,
+            Microsoft.Extensions.Logging.ILogger<StartupSelfTestService> logger,
+            StartupCheckReporter? reporter = null)
+            : base(serviceProvider, configuration, settings, logger, reporter)
+        {
+        }
+
+        protected override Task<bool> ProbeKeyVaultAsync(CancellationToken cancellationToken)
+        {
+            KeyVaultCalls++;
+            if (KeyVaultException is not null) throw KeyVaultException;
+            return Task.FromResult(KeyVaultResult);
+        }
+
+        protected override Task<bool> SendStartupEmailAsync(CancellationToken cancellationToken)
+        {
+            MailerCalls++;
+            return Task.FromResult(MailerResult);
+        }
+
+        protected override Task<bool> ProbeDatabaseAsync(CancellationToken cancellationToken)
+        {
+            DatabaseCalls++;
+            return Task.FromResult(DatabaseResult);
+        }
+
+        protected override Task<bool> ProbeMfrAsync(CancellationToken cancellationToken)
+        {
+            MfrCalls++;
+            return Task.FromResult(MfrResult);
+        }
+
+        protected override Task<bool> ProbePdfLicenseAsync(CancellationToken cancellationToken)
+        {
+            PdfLicenseCalls++;
+            return Task.FromResult(PdfLicenseResult);
+        }
+
+        public Task RunForTestAsync(CancellationToken cancellationToken)
+            => RunOnceAsync(cancellationToken);
+    }
+
+    /// <summary>Exposes the real (non-overridden) PDF license probe for direct testing.</summary>
+    private sealed class ProbeExposingStartupSelfTestService : StartupSelfTestService
+    {
+        public ProbeExposingStartupSelfTestService(
+            IServiceProvider serviceProvider,
+            IConfiguration configuration,
+            IOptions<StartupSelfTestSettings> settings,
+            Microsoft.Extensions.Logging.ILogger<StartupSelfTestService> logger)
+            : base(serviceProvider, configuration, settings, logger)
+        {
+        }
+
+        public Task<bool> InvokeProbePdfLicenseAsync(CancellationToken cancellationToken)
+            => ProbePdfLicenseAsync(cancellationToken);
+    }
+}

Fuchs.Tests/SystemStatusServiceTests.cs

@@ -0,0 +1,465 @@
+using System;
+using System.Collections.Generic;
+using System.Diagnostics.Metrics;
+using System.Threading;
+using System.Threading.Tasks;
+using Fuchs.Services;
+using Microsoft.Extensions.Configuration;
+using Microsoft.Extensions.DependencyInjection;
+using Microsoft.Extensions.Hosting;
+using Microsoft.Extensions.Logging.Abstractions;
+using Microsoft.Extensions.Options;
+using Moq;
+using Xunit;
+
+namespace Fuchs.Tests;
+
+/// <summary>
+/// Tests for the Admin module's read-only diagnostics service. Covers the passive config
+/// snapshot (SQL server parsing, email override reflection, presence flags), each probe's
+/// disabled/unconfigured/ok/error outcomes where deterministically reachable without live
+/// infrastructure, the test-email pipeline (success/failure/validation + HTML-encoding +
+/// override reporting), and the emitted probe telemetry.
+/// </summary>
+public class SystemStatusServiceTests
+{
+    private const string FuchsMeterName = "Fuchs.Intranet";
+
+    private static IConfiguration Config(Dictionary<string, string?>? overrides = null)
+    {
+        var dict = new Dictionary<string, string?>
+        {
+            ["ConnectionStrings:fuchs_fds_ConnectionString"] =
+                "Data Source=SQLHOST,1433;Initial Catalog=site_fuchs_test;User ID=fuchs_app;password='secret';",
+            ["ConnectionStrings:AzureBlobStorage_ConnectionString"] = "DefaultEndpointsProtocol=https;AccountName=acct;AccountKey=key==;",
+            ["Fuchs:IsTestDeployment"] = "true",
+            ["Fds:MFR_host"] = "portal.mobilefieldreport.com",
+            ["Fds:MFR_UserName"] = "mfruser",
+            ["Fds:SyncEnabled"] = "true",
+            ["SecretManagement:VaultUri"] = "https://vault.example/",
+            ["SecretManagement:AppName"] = "fuchs",
+            ["SecretManagement:ManagedSecretKeys:0"] = "Fuchs--Mailer--Token",
+            ["SecretManagement:ManagedSecretKeys:1"] = "ConnectionStrings--fuchs-fds-password",
+        };
+        if (overrides != null)
+            foreach (var kv in overrides) dict[kv.Key] = kv.Value;
+        return new ConfigurationBuilder().AddInMemoryCollection(dict).Build();
+    }
+
+    private static SystemStatusService Build(
+        IConfiguration? config = null,
+        Mock<IBlobStorageService>? blob = null,
+        Mock<IMfrClientFactory>? mfr = null,
+        Mock<IComService>? com = null,
+        ProcessWebComSettings? mailer = null,
+        FuchsEmailSettings? email = null,
+        AzureBlobStorageSettings? blobSettings = null,
+        IServiceProvider? provider = null,
+        StartupCheckReporter? startupChecks = null)
+    {
+        var env = new Mock<IHostEnvironment>();
+        env.SetupGet(e => e.EnvironmentName).Returns("Development");
+
+        return new SystemStatusService(
+            config ?? Config(),
+            env.Object,
+            provider ?? new ServiceCollection().BuildServiceProvider(),
+            (blob ?? new Mock<IBlobStorageService>()).Object,
+            (mfr ?? new Mock<IMfrClientFactory>()).Object,
+            (com ?? new Mock<IComService>()).Object,
+            Options.Create(mailer ?? new ProcessWebComSettings { Enabled = true, Token = "tok", BaseUrl = "https://api.example", AccountId = "acc", ServerId = "srv" }),
+            Options.Create(email ?? new FuchsEmailSettings()),
+            Options.Create(blobSettings ?? new AzureBlobStorageSettings { Enabled = true }),
+            startupChecks ?? new StartupCheckReporter(),
+            NullLogger<SystemStatusService>.Instance);
+    }
+
+    // ── GetInfo (passive snapshot) ─────────────────────────────────────────────
+    [Fact]
+    public void GetInfo_ParsesConnectionStringAndReflectsConfiguration()
+    {
+        var svc = Build();
+
+        SystemInfoSnapshot info = svc.GetInfo();
+
+        Assert.Equal("Development", info.Environment);
+        Assert.True(info.IsTestDeployment);
+        Assert.True(info.Database.Configured);
+        Assert.Equal("SQLHOST,1433", info.Database.Server);
+        Assert.Equal("site_fuchs_test", info.Database.Catalog);
+        Assert.Equal("fuchs_app", info.Database.UserId);   // login only, never the password
+        Assert.True(info.Mfr.CredentialsConfigured);
+        Assert.Equal("portal.mobilefieldreport.com", info.Mfr.Host);
+        Assert.True(info.Mfr.SyncEnabled);
+        Assert.Equal("fuchs", info.KeyVault.AppName);
+        Assert.Equal(2, info.KeyVault.ManagedSecretCount);
+        Assert.False(info.KeyVault.ClientRegistered);      // empty provider
+    }
+
+    [Fact]
+    public void GetInfo_NeverLeaksDatabasePassword()
+    {
+        var svc = Build();
+
+        SystemInfoSnapshot info = svc.GetInfo();
+
+        Assert.DoesNotContain("secret", info.Database.UserId ?? "");
+        Assert.DoesNotContain("secret", info.Database.Server ?? "");
+        Assert.DoesNotContain("secret", info.Database.Catalog ?? "");
+    }
+
+    [Theory]
+    [InlineData(true)]
+    [InlineData(false)]
+    public void GetInfo_EmailOverride_ReflectedOnlyWhenConfigured(bool overrideSet)
+    {
+        var email = new FuchsEmailSettings { OverrideRecipient = overrideSet ? "safety@example.test" : "" };
+        var svc = Build(email: email);
+
+        SystemInfoSnapshot info = svc.GetInfo();
+
+        Assert.Equal(overrideSet, info.Email.OverrideActive);
+        Assert.Equal(overrideSet ? "safety@example.test" : null, info.Email.OverrideRecipient);
+        Assert.True(info.Email.MailerEnabled);   // Build() default enables the mailer
+        Assert.True(info.Email.TokenConfigured);
+    }
+
+    [Fact]
+    public void GetInfo_StartupChecks_NullWhenServiceHasNotRun()
+    {
+        var svc = Build(startupChecks: new StartupCheckReporter());   // nothing set yet
+
+        Assert.Null(svc.GetInfo().StartupChecks);
+    }
+
+    [Fact]
+    public void GetInfo_StartupChecks_ReflectsReporterContents()
+    {
+        var reporter = new StartupCheckReporter();
+        reporter.Set(new StartupCheckReport
+        {
+            Ran = true,
+            CompletedUtc = DateTimeOffset.UtcNow,
+            MachineName = "BUILD-HOST",
+            Items =
+            [
+                new StartupCheckItem { Name = "Database", Enabled = true, Ok = true },
+                new StartupCheckItem { Name = "Mailer", Enabled = false, Ok = false },
+            ],
+        });
+        var svc = Build(startupChecks: reporter);
+
+        var report = svc.GetInfo().StartupChecks;
+
+        Assert.NotNull(report);
+        Assert.True(report!.Ran);
+        Assert.Equal("BUILD-HOST", report.MachineName);
+        Assert.Equal(2, report.Items.Count);
+        Assert.Contains(report.Items, i => i.Name == "Database" && i.Enabled && i.Ok);
+    }
+
+    [Fact]
+    public void GetInfo_DatabaseUnconfigured_WhenConnectionStringMissing()
+    {
+        var config = Config(new() { ["ConnectionStrings:fuchs_fds_ConnectionString"] = "" });
+        var svc = Build(config);
+
+        Assert.False(svc.GetInfo().Database.Configured);
+    }
+
+    // ── Blob probe ─────────────────────────────────────────────────────────────
+    [Fact]
+    public async Task ProbeBlob_Disabled_ReturnsDisabled()
+    {
+        var blob = new Mock<IBlobStorageService>();
+        blob.Setup(b => b.CheckConnectivityAsync(It.IsAny<CancellationToken>()))
+            .ReturnsAsync(new BlobConnectivity { Enabled = false });
+        var svc = Build(blob: blob);
+
+        var r = await svc.ProbeAsync("blob");
+
+        Assert.Equal("blob", r.Component);
+        Assert.Equal("disabled", r.Status);
+        Assert.False(r.Ok);
+    }
+
+    [Fact]
+    public async Task ProbeBlob_EnabledButUnconfigured_ReturnsUnconfigured()
+    {
+        var blob = new Mock<IBlobStorageService>();
+        blob.Setup(b => b.CheckConnectivityAsync(It.IsAny<CancellationToken>()))
+            .ReturnsAsync(new BlobConnectivity { Enabled = true, Configured = false, Detail = "keine Verbindungszeichenfolge" });
+        var svc = Build(blob: blob);
+
+        var r = await svc.ProbeAsync("blob");
+
+        Assert.Equal("unconfigured", r.Status);
+        Assert.False(r.Ok);
+    }
+
+    [Fact]
+    public async Task ProbeBlob_Reachable_ReturnsOkWithAccountDetail()
+    {
+        var blob = new Mock<IBlobStorageService>();
+        blob.Setup(b => b.CheckConnectivityAsync(It.IsAny<CancellationToken>()))
+            .ReturnsAsync(new BlobConnectivity { Enabled = true, Configured = true, Reachable = true, AccountName = "acct", Detail = "StorageV2 / Standard_LRS" });
+        var svc = Build(blob: blob);
+
+        var r = await svc.ProbeAsync("blob");
+
+        Assert.Equal("ok", r.Status);
+        Assert.True(r.Ok);
+        Assert.Contains("acct", r.Detail);
+    }
+
+    [Fact]
+    public async Task ProbeBlob_Reachable_ReportsFileCountsPerContainerAsMetrics()
+    {
+        var blob = new Mock<IBlobStorageService>();
+        blob.Setup(b => b.CheckConnectivityAsync(It.IsAny<CancellationToken>()))
+            .ReturnsAsync(new BlobConnectivity
+            {
+                Enabled = true, Configured = true, Reachable = true, AccountName = "acct",
+                Detail = "StorageV2 / Standard_LRS",
+                Containers = new List<BlobContainerCount>
+                {
+                    new() { Name = "dev-fuchs-invoices", Exists = true, FileCount = 42 },
+                    new() { Name = "dev-fuchs-reminders", Exists = false, FileCount = 0 },
+                },
+            });
+        var svc = Build(blob: blob);
+
+        var r = await svc.ProbeAsync("blob");
+
+        Assert.Equal("ok", r.Status);
+        Assert.NotNull(r.Metrics);
+        Assert.Equal(2, r.Metrics!.Count);
+        var inv = Assert.Single(r.Metrics, m => m.Label == "dev-fuchs-invoices");
+        Assert.Equal("42 Dateien", inv.Value);
+        var rem = Assert.Single(r.Metrics, m => m.Label == "dev-fuchs-reminders");
+        Assert.Equal("nicht vorhanden", rem.Value);
+        Assert.Contains("42 Dateien gesamt", r.Message);   // total across containers
+    }
+
+    [Fact]
+    public async Task ProbeBlob_FileCountUnavailable_ReportsMetricWithoutFailing()
+    {
+        var blob = new Mock<IBlobStorageService>();
+        blob.Setup(b => b.CheckConnectivityAsync(It.IsAny<CancellationToken>()))
+            .ReturnsAsync(new BlobConnectivity
+            {
+                Enabled = true, Configured = true, Reachable = true, AccountName = "acct",
+                Containers = new List<BlobContainerCount>
+                {
+                    new() { Name = "dev-fuchs-invoices", Exists = true, FileCount = -1 },
+                },
+            });
+        var svc = Build(blob: blob);
+
+        var r = await svc.ProbeAsync("blob");
+
+        Assert.Equal("ok", r.Status);
+        var inv = Assert.Single(r.Metrics!);
+        Assert.Equal("Anzahl nicht ermittelbar", inv.Value);
+    }
+
+    [Fact]
+    public async Task ProbeBlob_ConfiguredButUnreachable_ReturnsError()
+    {
+        var blob = new Mock<IBlobStorageService>();
+        blob.Setup(b => b.CheckConnectivityAsync(It.IsAny<CancellationToken>()))
+            .ReturnsAsync(new BlobConnectivity { Enabled = true, Configured = true, Reachable = false, AccountName = "acct", Detail = "403 Forbidden" });
+        var svc = Build(blob: blob);
+
+        var r = await svc.ProbeAsync("blob");
+
+        Assert.Equal("error", r.Status);
+        Assert.False(r.Ok);
+    }
+
+    // ── Key Vault probe ────────────────────────────────────────────────────────
+    [Fact]
+    public async Task ProbeKeyVault_ClientNotRegistered_ReturnsUnconfigured()
+    {
+        var svc = Build();   // empty service provider → no SecretClient
+
+        var r = await svc.ProbeAsync("keyvault");
+
+        Assert.Equal("keyvault", r.Component);
+        Assert.Equal("unconfigured", r.Status);
+        Assert.False(r.Ok);
+    }
+
+    [Fact]
+    public async Task ProbeKeyVault_NoManagedKeys_ReturnsUnconfigured()
+    {
+        var config = Config(new()
+        {
+            ["SecretManagement:ManagedSecretKeys:0"] = null,
+            ["SecretManagement:ManagedSecretKeys:1"] = null,
+        });
+        var svc = Build(config);
+
+        var r = await svc.ProbeAsync("keyvault");
+
+        Assert.Equal("unconfigured", r.Status);
+    }
+
+    // ── MFR probe ──────────────────────────────────────────────────────────────
+    [Fact]
+    public async Task ProbeMfr_FactoryThrows_ReturnsError()
+    {
+        var mfr = new Mock<IMfrClientFactory>();
+        mfr.Setup(f => f.Create()).Throws(new InvalidOperationException("no credentials"));
+        var svc = Build(mfr: mfr);
+
+        var r = await svc.ProbeAsync("mfr");
+
+        Assert.Equal("mfr", r.Component);
+        Assert.Equal("error", r.Status);
+        Assert.False(r.Ok);
+        Assert.Equal("no credentials", r.Detail);
+    }
+
+    // ── Database probe (unconfigured is deterministic without a live server) ────
+    [Fact]
+    public async Task ProbeDatabase_NoConnectionString_ReturnsUnconfigured()
+    {
+        var config = Config(new() { ["ConnectionStrings:fuchs_fds_ConnectionString"] = "" });
+        var svc = Build(config);
+
+        var r = await svc.ProbeAsync("database");
+
+        Assert.Equal("database", r.Component);
+        Assert.Equal("unconfigured", r.Status);
+        Assert.False(r.Ok);
+    }
+
+    // ── Unknown component ──────────────────────────────────────────────────────
+    [Fact]
+    public async Task ProbeAsync_UnknownComponent_ReturnsError()
+    {
+        var svc = Build();
+
+        var r = await svc.ProbeAsync("does-not-exist");
+
+        Assert.Equal("error", r.Status);
+        Assert.False(r.Ok);
+    }
+
+    [Fact]
+    public async Task ProbeAllAsync_ReturnsOneResultPerComponent()
+    {
+        var blob = new Mock<IBlobStorageService>();
+        blob.Setup(b => b.CheckConnectivityAsync(It.IsAny<CancellationToken>()))
+            .ReturnsAsync(new BlobConnectivity { Enabled = false });
+        var mfr = new Mock<IMfrClientFactory>();
+        mfr.Setup(f => f.Create()).Throws(new InvalidOperationException("x"));
+        var config = Config(new() { ["ConnectionStrings:fuchs_fds_ConnectionString"] = "" });
+        var svc = Build(config, blob: blob, mfr: mfr);
+
+        var results = await svc.ProbeAllAsync();
+
+        Assert.Equal(svc.ProbeComponents.Count, results.Count);
+        foreach (var comp in svc.ProbeComponents)
+            Assert.Contains(results, r => r.Component == comp);
+        Assert.All(results, r => Assert.True(r.DurationMs >= 0));
+    }
+
+    [Fact]
+    public async Task ProbeAsync_EmitsProbeTelemetry()
+    {
+        var blob = new Mock<IBlobStorageService>();
+        blob.Setup(b => b.CheckConnectivityAsync(It.IsAny<CancellationToken>()))
+            .ReturnsAsync(new BlobConnectivity { Enabled = false });
+        var svc = Build(blob: blob);
+
+        long delta = 0;
+        using var listener = new MeterListener
+        {
+            InstrumentPublished = (inst, l) =>
+            {
+                if (inst.Meter.Name == FuchsMeterName && inst.Name == "fuchs.systemstatus.probes")
+                    l.EnableMeasurementEvents(inst);
+            }
+        };
+        listener.SetMeasurementEventCallback<long>((_, value, _, _) => Interlocked.Add(ref delta, value));
+        listener.Start();
+
+        await svc.ProbeAsync("blob");
+
+        Assert.True(delta >= 1, "fuchs.systemstatus.probes counter should increment per probe.");
+    }
+
+    // ── Test email ─────────────────────────────────────────────────────────────
+    [Theory]
+    [InlineData("", "subj", "body")]
+    [InlineData("to@example.test", "", "body")]
+    public async Task SendTestEmailAsync_MissingRequiredFields_DoesNotSend(string to, string subject, string body)
+    {
+        var com = new Mock<IComService>();
+        var svc = Build(com: com);
+
+        var r = await svc.SendTestEmailAsync(to, subject, body);
+
+        Assert.False(r.Sent);
+        com.Verify(c => c.SendEmailAsync(It.IsAny<string>(), It.IsAny<string>(), It.IsAny<string>(),
+            It.IsAny<string>(), It.IsAny<string>(), It.IsAny<Dictionary<string, byte[]>>()), Times.Never);
+    }
+
+    [Fact]
+    public async Task SendTestEmailAsync_Success_SendsHtmlEncodedBodyToRecipient()
+    {
+        string? capturedHtml = null, capturedTo = null, capturedSubject = null;
+        var com = new Mock<IComService>();
+        com.Setup(c => c.SendEmailAsync(It.IsAny<string>(), It.IsAny<string>(), It.IsAny<string>(),
+                It.IsAny<string>(), It.IsAny<string>(), It.IsAny<Dictionary<string, byte[]>?>()))
+            .Callback<string, string, string, string, string, Dictionary<string, byte[]>?>(
+                (_, subj, html, to, _, _) => { capturedSubject = subj; capturedHtml = html; capturedTo = to; })
+            .ReturnsAsync(true);
+        var svc = Build(com: com);
+
+        var r = await svc.SendTestEmailAsync("dest@example.test", "Betreff", "Zeile1<script>\nZeile2");
+
+        Assert.True(r.Sent);
+        Assert.Equal("dest@example.test", capturedTo);
+        Assert.Equal("Betreff", capturedSubject);
+        Assert.NotNull(capturedHtml);
+        Assert.Contains("&lt;script&gt;", capturedHtml);       // HTML-encoded, not injected
+        Assert.DoesNotContain("<script>", capturedHtml);
+        Assert.Contains("<br/>", capturedHtml);                // newline → <br/>
+        Assert.Null(r.OverrideRecipient);
+    }
+
+    [Fact]
+    public async Task SendTestEmailAsync_OverrideActive_ReportsOverrideRecipient()
+    {
+        var com = new Mock<IComService>();
+        com.Setup(c => c.SendEmailAsync(It.IsAny<string>(), It.IsAny<string>(), It.IsAny<string>(),
+                It.IsAny<string>(), It.IsAny<string>(), It.IsAny<Dictionary<string, byte[]>?>()))
+            .ReturnsAsync(true);
+        var svc = Build(com: com, email: new FuchsEmailSettings { OverrideRecipient = "safety@example.test" });
+
+        var r = await svc.SendTestEmailAsync("dest@example.test", "Betreff", "Body");
+
+        Assert.True(r.Sent);
+        Assert.Equal("dest@example.test", r.RequestedRecipient);
+        Assert.Equal("safety@example.test", r.OverrideRecipient);
+        Assert.Contains("safety@example.test", r.Message);
+    }
+
+    [Fact]
+    public async Task SendTestEmailAsync_MailerRejects_ReturnsNotSent()
+    {
+        var com = new Mock<IComService>();
+        com.Setup(c => c.SendEmailAsync(It.IsAny<string>(), It.IsAny<string>(), It.IsAny<string>(),
+                It.IsAny<string>(), It.IsAny<string>(), It.IsAny<Dictionary<string, byte[]>?>()))
+            .ReturnsAsync(false);
+        var svc = Build(com: com);
+
+        var r = await svc.SendTestEmailAsync("dest@example.test", "Betreff", "Body");
+
+        Assert.False(r.Sent);
+        Assert.Equal("dest@example.test", r.RequestedRecipient);
+    }
+}

Fuchs/Controllers/IntranetController.Admin.cs

@@ -0,0 +1,107 @@
+using Fuchs.Services;
+using Microsoft.AspNetCore.Mvc;
+using Newtonsoft.Json;
+using Newtonsoft.Json.Serialization;
+using OCORE.SQL;
+using static OCORE.SQL.sql;
+using static OCORE.web.mvc_helper_async;
+
+namespace Fuchs.Controllers;
+
+// Partial class: Admin / system-status module.
+//
+// Access is restricted to users whose "fds_sys" module authorization is greater than 4.
+// The menu button is only shown, and the module script only loaded, for such users (frontend),
+// but every data endpoint here ALSO enforces the level server-side (defense in depth) — the
+// passive/probe data is diagnostic and must never be reachable by a lower-privileged session.
+public partial class IntranetController
+{
+    // fds_sys authorization must exceed this to use the Admin module.
+    private const int AdminMinAuthExclusive = 4;
+
+    private async Task<IActionResult> Do_Process_Admin(string fn, string id, string code)
+    {
+        _logger.LogDebug("Do_Process_Admin action={Action} code={Code} user={User}", id, code, UserAccountID);
+
+        // The auth probe is the one endpoint that answers for BOTH authorized and unauthorized
+        // users (the frontend uses manage>0 to decide whether to render the module at all).
+        int authLevel = await GetSystemAdminAuthAsync(fn, id, code);
+        bool authorized = authLevel > AdminMinAuthExclusive;
+
+        if (id.Equals("auth", StringComparison.OrdinalIgnoreCase))
+            return await JSONAsync(new { manage = authorized ? 1 : 0, level = authLevel });
+
+        if (!authorized)
+        {
+            _logger.LogWarning("Admin access denied for user={User} (fds_sys={Level}) action={Action}",
+                UserAccountID, authLevel, id);
+            return Unauthorized401();
+        }
+
+        var status = _systemStatus;
+        switch (id.ToLowerInvariant())
+        {
+            case "status":
+            {
+                var info = status.GetInfo();
+                var probes = await status.ProbeAllAsync(HttpContext.RequestAborted);
+                return AdminJson(new { info, probes });
+            }
+
+            case "info":
+                return AdminJson(new { info = status.GetInfo() });
+
+            case "probe":
+            {
+                // code carries the component id, e.g. /do/admin/probe/database
+                string component = string.IsNullOrWhiteSpace(code) ? Form("component") : code;
+                if (string.IsNullOrWhiteSpace(component))
+                    return BadRequest400();
+                var probe = await status.ProbeAsync(component, HttpContext.RequestAborted);
+                return AdminJson(new { probe });
+            }
+
+            case "testmail":
+            {
+                if (!HasForm("to", "subject"))
+                    return BadRequest400();
+                var result = await status.SendTestEmailAsync(
+                    Form("to"), Form("subject"), Form("body"), HttpContext.RequestAborted);
+                _logger.LogInformation("Admin test email requested by user={User} to={To} sent={Sent}",
+                    UserAccountID, result.RequestedRecipient, result.Sent);
+                return AdminJson(new { result });
+            }
+
+            default:
+                _logger.LogWarning("Admin: no handler for action={Action}, user={User}", id, UserAccountID);
+                return BadRequest400();
+        }
+    }
+
+    // The status DTOs (SystemInfoSnapshot / SystemProbeResult) are PascalCase; serialize them
+    // camelCase so the Admin frontend contract matches the lowercase convention used elsewhere.
+    private static readonly JsonSerializerSettings CamelCaseJson = new()
+    {
+        ContractResolver = new CamelCasePropertyNamesContractResolver(),
+    };
+
+    // Mirror OCORE's getJSONResult exactly (application/json; charset=utf-8) so the response
+    // parses identically to every other endpoint the frontend's postXT talks to.
+    private ContentResult AdminJson(object payload) =>
+        Content(JsonConvert.SerializeObject(payload, CamelCaseJson), "application/json; charset=utf-8");
+
+    /// <summary>
+    /// Resolves the calling user's <c>fds_sys</c> module authorization level via the
+    /// <c>fis_getModuleAuth</c> SQL function (same mechanism as <see cref="HandleAuth"/>).
+    /// Returns -3 when it cannot be determined (fail-closed).
+    /// </summary>
+    private async Task<int> GetSystemAdminAuthAsync(string fn, string id, string code)
+    {
+        var val = await getSQLValue_async<int>(
+            "SELECT [dbo].[fis_getModuleAuth](@module, @authuser);",
+            _intranet.Intranet__SQLConnectionString, -3,
+            StdParamlist(SQL_VarChar("@module", "fds_sys")),
+            Security: DbSec, options: SqlOpt(fn, id, code));
+        return val.Result;
+    }
+}

Fuchs/Controllers/IntranetController.Banking.cs

@@ -22,8 +22,9 @@ public partial class IntranetController
                 return await JSONAsync(new { manage = 1 });
 
             case "up":
-                _logger.LogInformation("Banking MT940 upload: {FileCount} file(s) user={User}",
+                _logger.LogInformation("Banking statement upload: {FileCount} file(s) user={User}",
                     Request.Form.Files.Count, UserAccountID);
+                var uploadResults = new List<object>();
                 foreach (var fle in Request.Form.Files)
                 {
                     using var stream = fle.OpenReadStream();
@@ -34,6 +35,9 @@ public partial class IntranetController
 
                     var tbl    = _banking.ParseToDatatable(stream, schemaDt);
                     var tmptbl = "bs_" + Guid.NewGuid().ToString().Replace("-", "");
+                    var (importFrom, importTo) = BankingDateRange(tbl);
+                    bool importFailed = false;
+                    string importFailure = "";
 
                     var dtwa = new DatatableWriterAsync(tbl, _intranet.Intranet__SQLConnectionString)
                     {
@@ -48,16 +52,80 @@ public partial class IntranetController
                     dtwa.CommandAfterError = new SqlCommand(
                         $"SELECT * INTO [{tmptbl}] FROM {dtwa.DestinationTableName};");
                     dtwa.OnError += (_, exc, _) =>
+                    {
+                        importFailed = true;
+                        importFailure = exc.Message;
+                        _logger.LogError(exc,
+                            "Banking upload SQL exception — file={File} destTable={DestTable} user={User}",
+                            fle.FileName, dtwa.DestinationTableName, UserAccountID);
                         _intranet.debug_log("IntranetController.bam.up - sql exception",
                             exc, UserAccountID, new { uid = dtwa.InstanceGUID, tmptbl });
+                    };
                     dtwa.OnCommandAfterError += (_, exc) =>
+                    {
+                        importFailed = true;
+                        importFailure = exc.Message;
+                        _logger.LogError(exc,
+                            "Banking upload merge-command exception — file={File} destTable={DestTable} " +
+                            "rescueTable={RescueTable} user={User}",
+                            fle.FileName, dtwa.DestinationTableName, tmptbl, UserAccountID);
                         _intranet.debug_log("IntranetController.bam.up - command-after exception",
                             exc, UserAccountID, new { uid = dtwa.InstanceGUID, tmptbl });
+                    };
                     _logger.LogDebug("Banking upload parsed {Rows} rows → temp table submit (user={User})",
                         tbl.Rows.Count, UserAccountID);
                     dtwa.DoSubmit();
+                    if (dtwa.SubmitException != null)
+                    {
+                        importFailed = true;
+                        importFailure = dtwa.SubmitException.Message;
+                        _logger.LogError(dtwa.SubmitException,
+                            "Banking upload submit exception — file={File} destTable={DestTable} user={User}",
+                            fle.FileName, dtwa.DestinationTableName, UserAccountID);
                     }
-                return Ok();
+
+                    if (importFailed)
+                    {
+                        _logger.LogError(
+                            "Banking import failed — file={File} rows={Rows} reason={Reason} user={User}",
+                            fle.FileName, tbl.Rows.Count, importFailure, UserAccountID);
+                        await _events.BankingImportIssueAsync(
+                            $"Kontobewegungen aus {fle.FileName} konnten nicht importiert werden: {importFailure}",
+                            fle.FileName, UserAccountID);
+                    }
+                    else if (tbl.Rows.Count == 0)
+                    {
+                        // Parsing produced zero rows — check the preceding "Bank statement parsed"
+                        // warning from BankingService for the reason (missing account element,
+                        // unsupported schema variant, empty file, ...).
+                        _logger.LogWarning(
+                            "Banking import: 0 rows parsed from {File} — nothing to import. user={User}",
+                            fle.FileName, UserAccountID);
+                        await _events.BankingImportIssueAsync(
+                            $"Aus {fle.FileName} konnten keine Kontobewegungen importiert werden.",
+                            fle.FileName, UserAccountID);
+                    }
+                    else
+                    {
+                        _logger.LogInformation(
+                            "Banking import succeeded — file={File} rows={Rows} from={From} to={To} user={User}",
+                            fle.FileName, tbl.Rows.Count, importFrom, importTo, UserAccountID);
+                        await _events.BankingTransactionsImportedAsync(
+                            importFrom, importTo, tbl.Rows.Count, fle.FileName, UserAccountID);
+                    }
+
+                    uploadResults.Add(new
+                    {
+                        fileName = fle.FileName,
+                        rows     = tbl.Rows.Count,
+                        success  = !importFailed && tbl.Rows.Count > 0,
+                        error    = importFailed ? importFailure : ""
+                    });
+                }
+                // Return a JSON body: the frontend posts with dataType 'json', so an
+                // empty 200 would be reported as a parse error and surface the generic
+                // "auth failed" alert even though the import actually succeeded.
+                return await JSONAsync(new { ok = true, files = uploadResults });
 
             case "qtl":
             {
@@ -122,11 +190,21 @@ public partial class IntranetController
             {
                 if (!HasForm("taid")) return BadRequest400();
                 var pl  = StdParamlist(SQL_VarChar("@taID", Form("taid"), dbNull_IfEmpty: true));
-                var res = await getSQLValue_async(
+                var res = await getSQLDatatable_async(
                     "EXECUTE [dbo].[fds__setBankingtransaction_done] @taID, @authuser;",
                     _intranet.Intranet__SQLConnectionString, pl,
                     Security: DbSec, options: SqlOpt(fn, id, code));
-                return res.Result is true ? Ok() : StatusCode(500, new { error = "not successful" });
+                var row = res.FirstRow;
+                bool success = row["success"] is true;
+                if (success)
+                {
+                    DateTime? valueDate = row["ValueDate"] == DBNull.Value ? null : (DateTime)row["ValueDate"];
+                    decimal? amount = row["Amount"] == DBNull.Value ? null : (decimal)row["Amount"];
+                    await _events.BankingTransactionMarkedDoneAsync(Form("taid"), valueDate, amount, UserAccountID);
+                }
+                return success
+                    ? await JSONAsync(new { ok = true })
+                    : StatusCode(500, new { error = "not successful" });
             }
 
             case "ati":
@@ -139,7 +217,55 @@ public partial class IntranetController
                     "EXECUTE [dbo].[fds__setBankingtransaction_assignToIvoice] @taID, @invoice_id, @authuser;",
                     _intranet.Intranet__SQLConnectionString, pl,
                     Security: DbSec, options: SqlOpt(fn, id, code));
-                return res.Result is true ? Ok() : StatusCode(500, new { error = "not successful" });
+                return res.Result is true
+                    ? await JSONAsync(new { ok = true })
+                    : StatusCode(500, new { error = "not successful" });
+            }
+
+            case "man":
+            {
+                var pl = StdParamlist(
+                    SQL_VarChar("@taID", Form("taID"), dbNull_IfEmpty: true),
+                    SQL_Date("@ValueDate", Form("ValueDate")),
+                    SQL_Decimal("@Amount", Form("Amount"), precision: 9, scale: 2),
+                    SQL_NVarChar("@NameOfPayer", Form("NameOfPayer"), dbNull_IfEmpty: true),
+                    SQL_VarChar("@SepaRemittanceInformation", Form("SepaRemittanceInformation"), dbNull_IfEmpty: true));
+                await getSQLDatatable_async(
+                    "EXECUTE [dbo].[fds__setBankingtransaction_manual] @taID, @ValueDate, @Amount, @NameOfPayer, @SepaRemittanceInformation, @authuser;",
+                    _intranet.Intranet__SQLConnectionString, pl,
+                    Security: DbSec, options: SqlOpt(fn, id, code));
+                _logger.LogInformation(
+                    "Manual banking transaction upserted taID={TaID} user={User}", Form("taID"), UserAccountID);
+                return await JSONAsync(new { ok = true });
+            }
+
+            case "mget":
+            {
+                if (!HasForm("taid")) return BadRequest400();
+                var pl  = StdParamlist(SQL_VarChar("@taID", Form("taid"), dbNull_IfEmpty: true));
+                var res = await getSQLDatatable_async(
+                    "EXECUTE [dbo].[fds__getBankingtransaction_manual] @taID, @authuser;",
+                    _intranet.Intranet__SQLConnectionString, pl,
+                    Security: DbSec, options: SqlOpt(fn, id, code));
+                return await JSONAsync(res.FirstRow.toObjectDictionary());
+            }
+
+            case "mdel":
+            {
+                if (!HasForm("taid")) return BadRequest400();
+                var pl = StdParamlist(
+                    SQL_VarChar("@taID", Form("taid"), dbNull_IfEmpty: true),
+                    SQL_Date("@ValueDate", (string?)null),
+                    SQL_Decimal("@Amount", (string?)null, precision: 9, scale: 2),
+                    SQL_NVarChar("@NameOfPayer", null, dbNull_IfEmpty: true),
+                    SQL_VarChar("@SepaRemittanceInformation", null, dbNull_IfEmpty: true));
+                await getSQLDatatable_async(
+                    "EXECUTE [dbo].[fds__setBankingtransaction_manual] @taID, @ValueDate, @Amount, @NameOfPayer, @SepaRemittanceInformation, @authuser;",
+                    _intranet.Intranet__SQLConnectionString, pl,
+                    Security: DbSec, options: SqlOpt(fn, id, code));
+                _logger.LogInformation(
+                    "Manual banking transaction deleted taID={TaID} user={User}", Form("taid"), UserAccountID);
+                return await JSONAsync(new { ok = true });
             }
 
             case "vfi":
@@ -155,14 +281,47 @@ public partial class IntranetController
             }
 
             default:
-                return Ok();
+                return await JSONAsync(new { ok = true });
         }
     }
 
     // ── Form helpers ─────────────────────────────────────────────────────────
+    // Reads from the posted form when available, falling back to the query string. This
+    // supports endpoints in _allowedGet (e.g. req/idoc, rem/idoc) that are invoked via a
+    // plain GET (window.open with '?id=...'), where Request.Form has no Content-Type and
+    // would otherwise throw InvalidOperationException.
     protected bool HasForm(params string[] keys) =>
-        keys.All(k => Request.Form.ContainsKey(k) && !string.IsNullOrWhiteSpace(Request.Form[k]));
+        keys.All(k => !string.IsNullOrWhiteSpace(FormValue(k)));
 
     protected string Form(string key, string fallback = "") =>
-        Request.Form.TryGetValue(key, out var v) ? v.ToString() : fallback;
+        FormValue(key) ?? fallback;
+
+    private string? FormValue(string key) =>
+        RequestValueHelper.Resolve(
+            Request.HasFormContentType,
+            Request.HasFormContentType ? Request.Form : Microsoft.AspNetCore.Http.FormCollection.Empty,
+            Request.Query,
+            key);
+
+    private static (DateTime? From, DateTime? To) BankingDateRange(System.Data.DataTable tbl)
+    {
+        DateTime? from = null;
+        DateTime? to = null;
+        foreach (System.Data.DataRow row in tbl.Rows)
+        {
+            DateTime? date = BankingRowDate(row, tbl.Columns.Contains("EntryDate") ? "EntryDate" : "")
+                ?? BankingRowDate(row, tbl.Columns.Contains("ValueDate") ? "ValueDate" : "");
+            if (date == null) continue;
+            from = from == null || date.Value < from.Value ? date.Value : from;
+            to = to == null || date.Value > to.Value ? date.Value : to;
+        }
+        return (from, to);
+    }
+
+    private static DateTime? BankingRowDate(System.Data.DataRow row, string column)
+    {
+        if (string.IsNullOrEmpty(column) || row[column] == DBNull.Value) return null;
+        if (row[column] is DateTime dt) return dt.Date;
+        return DateTime.TryParse(row[column]?.ToString(), out var parsed) ? parsed.Date : null;
+    }
 }

Fuchs/Controllers/IntranetController.InvoiceDraft.cs

@@ -0,0 +1,130 @@
+using Fuchs.intranet;
+using Fuchs.Services;
+using Microsoft.AspNetCore.Mvc;
+using Newtonsoft.Json;
+using Newtonsoft.Json.Linq;
+using static OCORE.web.mvc_helper_async;
+
+namespace Fuchs.Controllers;
+
+// Partial class: live, backend-authoritative invoice draft editing (ADR 0006).
+// The browser posts single edits here; the server mutates the in-memory session
+// (the source of truth), recomputes/validates, and pings the editing browser over
+// SignalR (draftReady) to re-fetch. Commands are ordinary POSTs — the hub carries
+// only signals (ADR 0007).
+public partial class IntranetController
+{
+    /// <summary>Standard 410 when a session token is unknown/expired — the client re-opens the draft.</summary>
+    private IActionResult DraftGone() => StatusCode(410, new { error = "expired" });
+
+    // POST inv/dopen — { payload } → { token, version }
+    // The editor assembles the initial draft (from a service request or a reloaded DB draft
+    // via the existing render paths) and seeds the authoritative session here. Reload/discard
+    // is the client re-fetching + re-seeding, so there is no server-side DB reshaping.
+    private async Task<IActionResult> HandleDraftOpen(string fn, string id, string code)
+    {
+        if (!HasForm("payload"))
+        {
+            _logger.LogWarning("Draft dopen: 'payload' missing user={User}", UserAccountID);
+            return BadRequest400();
+        }
+        JObject payload;
+        try { payload = JObject.Parse(Form("payload")); }
+        catch (JsonException ex)
+        {
+            _logger.LogWarning(ex, "Draft dopen: invalid payload JSON user={User}", UserAccountID);
+            return BadRequest400();
+        }
+        var session = _invoiceDrafts.OpenFromPayload(payload, UserAccountID);
+        _logger.LogInformation("Draft dopen: session {Token} (invId={InvId}) user={User}", session.Token, session.InvId, UserAccountID);
+        // The browser holds the token from this response and fetches dstate directly; there is
+        // no server 'draftReady' on open (it would race the client's group-join). Signals drive
+        // only subsequent server-side changes.
+        return await JSONAsync(new { token = session.Token, version = session.Version });
+    }
+
+    // POST inv/dstate — { token } → full view state
+    private async Task<IActionResult> HandleDraftState(string fn, string id, string code)
+    {
+        if (!HasForm("token")) return BadRequest400();
+        var session = _invoiceDrafts.Get(Form("token"));
+        if (session == null) return DraftGone();
+        return await JSONAsync(_invoiceDrafts.BuildState(session));
+    }
+
+    // POST inv/dpatch — { token, delta } → { ok, version }; signals draftReady
+    private async Task<IActionResult> HandleDraftPatch(string fn, string id, string code)
+    {
+        if (!HasForm("token", "delta")) return BadRequest400();
+        InvoiceDraftDelta? delta;
+        try { delta = JsonConvert.DeserializeObject<InvoiceDraftDelta>(Form("delta")); }
+        catch (JsonException ex)
+        {
+            _logger.LogWarning(ex, "Draft dpatch: invalid delta JSON user={User}", UserAccountID);
+            return BadRequest400();
+        }
+        if (delta == null || string.IsNullOrEmpty(delta.Target)) return BadRequest400();
+
+        var session = _invoiceDrafts.ApplyPatch(Form("token"), delta);
+        if (session == null) return DraftGone();
+        await _draftNotifier.SignalDraftReadyAsync(session.Token, session.Version);
+        return await JSONAsync(new { ok = true, version = session.Version });
+    }
+
+    // POST inv/dpreview — { token } → { img[], total } (rendered straight from the cache)
+    private async Task<IActionResult> HandleDraftPreview(string fn, string id, string code)
+    {
+        if (!HasForm("token")) return BadRequest400();
+        var doc = _invoiceDrafts.RenderPreview(Form("token"));
+        if (doc == null) return DraftGone();
+        var imgcol = await _pdf.DocToImageCollectionAsync(doc);
+        return await JSONAsync(new { img = imgcol.ImgB64Array, total = imgcol.TotalPages });
+    }
+
+    // POST inv/dsave — { token } → { ok, invid }; flush cache→DB + business event + draftReady
+    private async Task<IActionResult> HandleDraftSave(string fn, string id, string code)
+    {
+        if (!HasForm("token")) return BadRequest400();
+        string token = Form("token");
+        var before = _invoiceDrafts.Get(token);
+        if (before == null) return DraftGone();
+        bool existed = !string.IsNullOrEmpty(before.InvId);
+
+        var fdInv = await _invoiceDrafts.FlushToDbAsync(token, UserAccountID, DbSec);
+        if (fdInv == null) return DraftGone();
+        if (string.IsNullOrEmpty(fdInv.Id))
+            return await InvoiceIssueResult("Der Zwischenstand konnte aufgrund eines Fehlers nicht gespeichert werden.");
+
+        await _events.InvoiceDraftRegisteredAsync(fdInv, existed, UserAccountID);
+        var after = _invoiceDrafts.Get(token);
+        if (after != null) await _draftNotifier.SignalDraftReadyAsync(after.Token, after.Version);
+        return await JSONAsync(new { ok = true, invid = fdInv.Id });
+    }
+
+    // POST inv/dhistory — { token } → { history[] }
+    private async Task<IActionResult> HandleDraftHistory(string fn, string id, string code)
+    {
+        if (!HasForm("token")) return BadRequest400();
+        if (_invoiceDrafts.Get(Form("token")) == null) return DraftGone();
+        var history = _invoiceDrafts.GetHistory(Form("token"))
+            .Select(h => new
+            {
+                timestamp = h.TimestampUtc,
+                target    = h.Target,
+                @ref      = h.Ref,
+                oldValue  = h.OldValue,
+                newValue  = h.NewValue,
+                version   = h.Version
+            });
+        return await JSONAsync(new { history });
+    }
+
+    // POST inv/dclose — { token } → { ok }
+    private async Task<IActionResult> HandleDraftClose(string fn, string id, string code)
+    {
+        if (!HasForm("token")) return BadRequest400();
+        bool ok = _invoiceDrafts.Close(Form("token"));
+        _logger.LogDebug("Draft dclose token={Token} removed={Removed} user={User}", Form("token"), ok, UserAccountID);
+        return await JSONAsync(new { ok });
+    }
+}

Fuchs/Controllers/IntranetController.Invoices.cs

@@ -36,7 +36,7 @@ public partial class IntranetController
                         StdParamlist(SQL_VarChar("@Id", invoiceId)),
                         Security: DbSec, options: SqlOpt(fn, id, code));
                     if (!ok) _logger.LogError("setpyd: SQL failed for invoice {InvoiceId}, user={User}", invoiceId, UserAccountID);
-                    return ok ? Ok() : StatusCode(500);
+                    return ok ? await JSONAsync(new { ok = true }) : StatusCode(500);
                 }
 
             case "setupd":
@@ -50,7 +50,7 @@ public partial class IntranetController
                         StdParamlist(SQL_VarChar("@Id", invoiceId)),
                         Security: DbSec, options: SqlOpt(fn, id, code));
                     if (!ok) _logger.LogError("setupd: SQL failed for invoice {InvoiceId}, user={User}", invoiceId, UserAccountID);
-                    return ok ? Ok() : StatusCode(500);
+                    return ok ? await JSONAsync(new { ok = true }) : StatusCode(500);
                 }
 
             case "setvat":
@@ -72,7 +72,7 @@ public partial class IntranetController
                         _intranet.Intranet_SqlCon(), ref sqlEx, ref sqlCode, pl, Security: DbSec);
                     if (!string.IsNullOrEmpty(sqlEx))
                         _logger.LogError("setvat: SQL error for report {ReportId}: {SqlError}, user={User}", Form("id"), sqlEx, UserAccountID);
-                    return string.IsNullOrEmpty(sqlEx) ? Ok() : StatusCode(500, new { error = sqlEx });
+                    return string.IsNullOrEmpty(sqlEx) ? await JSONAsync(new { ok = true }) : StatusCode(500, new { error = sqlEx });
                 }
 
             case "sis":
@@ -86,8 +86,15 @@ public partial class IntranetController
                         _intranet.Intranet__SQLConnectionString, pl,
                         Security: DbSec, options: SqlOpt(fn, id, code));
                     if (!string.IsNullOrEmpty(dt2.Exception))
+                    {
                         _logger.LogError("sis: SQL error for invoice {InvoiceId}: {SqlError}, user={User}", invoiceId, dt2.Exception, UserAccountID);
-                    return string.IsNullOrEmpty(dt2.Exception) ? Ok() : StatusCode(500);
+                        await _events.InvoiceIssueAsync(
+                            $"Rechnung {invoiceId} konnte nicht als versandt markiert werden.",
+                            UserAccountID, invoiceId);
+                    }
+                    else
+                        await _events.InvoiceMarkedSentAsync(invoiceId, invoiceId, UserAccountID);
+                    return string.IsNullOrEmpty(dt2.Exception) ? await JSONAsync(new { ok = true }) : StatusCode(500);
                 }
 
             case "pget":
@@ -149,11 +156,20 @@ public partial class IntranetController
                 using (var mfr = _mfrFactory.Create())
                     await mfr.Update__entitytable(EntityTypes.Invoice,
                         fds.FdsMfr.UpdateNeed.Reset, new[] { relId });
-                return Ok();
+                return await JSONAsync(new { ok = true });
+
+            // ── Live backend-authoritative draft editing (ADR 0006) ───────────
+            case "dopen":    return await HandleDraftOpen(fn, id, code);
+            case "dstate":   return await HandleDraftState(fn, id, code);
+            case "dpatch":   return await HandleDraftPatch(fn, id, code);
+            case "dpreview": return await HandleDraftPreview(fn, id, code);
+            case "dsave":    return await HandleDraftSave(fn, id, code);
+            case "dhistory": return await HandleDraftHistory(fn, id, code);
+            case "dclose":   return await HandleDraftClose(fn, id, code);
 
             default:
                 _logger.LogWarning("Do_Process_Invoices: unhandled action id={Id}, user={User}", id, UserAccountID);
-                return Ok();
+                return await JSONAsync(new { ok = true });
         }
     }
 }

Fuchs/Controllers/IntranetController.Invoices2.cs

@@ -58,7 +58,7 @@ public partial class IntranetController
             _logger.LogInformation("HandleInvoicePget reset complete for tgtid={TgtId} invoices={InvCount} serviceRequests={SrqCount} user={User}",
                 tgtid, invIds.Count, srqIds.Count, UserAccountID);
         }
-        return Ok();
+        return await JSONAsync(new { ok = true });
     }
 
     private async Task<IActionResult> HandleInvoiceGet(string fn, string id, string code)
@@ -78,16 +78,30 @@ public partial class IntranetController
             var ldic     = BuildInvoiceRequestList(sqldset);
             var adminDic = sqldset.Table("admin").FirstRow.toObjectDictionary();
             var invDic   = sqldset.Table("inv").FirstRow.toObjectDictionary();
-            bool has13b  = invDic.nz("InvoiceOptions", "").Split(',').Contains("§13b");
+            string invoiceOptions = invDic.nz("InvoiceOptions", "");
+            bool has13b  = invoiceOptions.Split(',').Contains("§13b");
             if (has13b)
                 adminDic["p13b"] = true;
+            // Carry the persisted set-pricing mode forward (see InvoiceSetPricing.cs / FdsInvoiceData.BuildInvoiceOptions):
+            // needed so the editor knows the invoice has already been explicitly switched to a set-display
+            // mode (including the default "setprice") and hides the "Set-Preisanzeige" menu entry accordingly.
+            string? setmodeToken = invoiceOptions.Split(',')
+                .FirstOrDefault(t => t.StartsWith("setmode:", StringComparison.OrdinalIgnoreCase));
+            if (setmodeToken != null)
+                adminDic["setmode"] = setmodeToken["setmode:".Length..].Trim().ToLowerInvariant();
             _logger.LogDebug("HandleInvoiceGet invoiceId={InvoiceId} requestCount={ReqCount} has13b={Has13b} user={User}",
                 invoiceId, ldic.Count, has13b, UserAccountID);
             return await JSONAsync(new { admin = adminDic, inv = invDic, req = ldic });
         }
         catch (Exception ex)
         {
-            _logger.LogError(ex, "HandleInvoiceGet failed for id={InvoiceId} user={User}", Form("id"), UserAccountID);
+            string invoiceId = Form("id");
+            _logger.LogError(ex, "HandleInvoiceGet failed for id={InvoiceId} user={User}", invoiceId, UserAccountID);
+            // This handler has its own catch (returns 500) and so never reaches the Do safety net;
+            // notify the user here so a failed invoice load is not silently swallowed.
+            await _events.InvoiceIssueAsync(
+                "Die Rechnung konnte aufgrund eines Fehlers nicht geladen werden.",
+                UserAccountID, invoiceId);
             return StatusCode(500);
         }
     }
@@ -390,6 +404,20 @@ public partial class IntranetController
                     var d = sitm.toObjectDictionary();
                     double net   = Convert.ToDouble(d.no("value_total", 0));
                     double vat   = Convert.ToDouble(d.no("vat", 0));
+                    double value = Convert.ToDouble(d.no("value", 0));
+                    string quantityStr = d.nz("Quantity");
+                    // quantityhours/UnitString reconstruct the hour-based quantity editor's raw
+                    // fields (e.g. "5 Std" -> quantityhours=5, UnitString="Std") from the persisted
+                    // "Quantity" string, mirroring the legacy fds__invoice_data ndic mapping — without
+                    // this, re-editing a reloaded hour-based item showed an empty quantity field.
+                    object quantityHours = "";
+                    if (value != 0 && !string.IsNullOrEmpty(quantityStr))
+                    {
+                        long qh = (long)(net / value);
+                        if (quantityStr.StartsWith(qh.ToString(CultureInfo.InvariantCulture) + " ", StringComparison.Ordinal))
+                            quantityHours = qh;
+                    }
+                    string unitString = !string.IsNullOrEmpty(quantityStr) ? quantityStr.RightFromFirst(" ") : "";
                     itm.Add(new Dictionary<string, object?>
                     {
                         ["Id"]         = d["Id"],
@@ -399,8 +427,11 @@ public partial class IntranetController
                         ["svcnet_val"] = d.no("value_service", 0),
                         ["net"]        = d.no("value", 0),
                         ["quantity"]   = d["Quantity"],
+                        ["quantityhours"] = quantityHours,
+                        ["UnitString"] = unitString,
                         ["Type"]       = d["Type"],
                         ["Note"]       = null,
+                        ["NameOrNumber"] = "",
                         ["htmltext"]   = d["Text"],
                         ["position"]   = d["Position"],
                         ["SortOrder"]  = d["SortOrder"]

Fuchs/Controllers/IntranetController.Reminder.cs

@@ -22,7 +22,9 @@ public partial class IntranetController
         {
             case "get":
             {
-                if (!HasForm("id")) return BadRequest400();
+                if (!HasForm("id")) { _logger.LogWarning("Reminder get: missing form field 'id', user={User}", UserAccountID); return BadRequest400(); }
+                _logger.LogDebug("Reminder get: preparing reminder for invoice {InvId} type={Type} level={Level} user={User}",
+                    Form("id"), Form("type"), Form("level"), UserAccountID);
                 var pl = StdParamlist(
                     SQL_VarChar("@InvId", Form("id")),
                     SQL_VarChar("@type",  Form("type")),
@@ -32,41 +34,61 @@ public partial class IntranetController
                     _intranet.Intranet__SQLConnectionString, pl,
                     tablenames: new[] { "rem" },
                     Security: DbSec, options: SqlOpt(fn, id, code));
+                if (!string.IsNullOrEmpty(dset.Exception))
+                    _logger.LogError("Reminder get: SQL error for invoice {InvId}: {SqlError}, user={User}", Form("id"), dset.Exception, UserAccountID);
                 return await JSONAsync(new { rm = dset.Table("rem").FirstRow.toObjectDictionary() });
             }
 
             case "prep":
             {
-                if (!HasForm("remc")) return BadRequest400();
+                if (!HasForm("remc")) { _logger.LogWarning("Reminder prep: missing form field 'remc', user={User}", UserAccountID); return BadRequest400(); }
+                _logger.LogInformation("Reminder prep: creating draft reminder, user={User}", UserAccountID);
                 var ctd   = JsonConvert.DeserializeObject(Form("remc"))!;
                 var fdRem = await _reminders.RegisterReminderAsync(
                     new FdsReminderData(ctd), change: false, remId: "", UserAccountID, DbSec);
                 if (!string.IsNullOrEmpty(fdRem.Id))
                 {
+                    _logger.LogInformation("Reminder prep: draft reminder {RemId} created, user={User}", fdRem.Id, UserAccountID);
+                    await _events.ReminderDraftCreatedAsync(fdRem, UserAccountID);
                     var imgcol = await _pdf.DocToImageCollectionAsync(_reminders.GenerateReminderPdf(fdRem, fdRem.IsDraft));
                     return await JSONAsync(new { id = fdRem.Id, img = imgcol.ImgB64Array, total = imgcol.TotalPages });
                 }
-                return StatusCode(500, new { error = "Erinnerung wurde nicht registriert" });
+                return await ReminderIssueResult("Die Mahnung konnte aufgrund eines Fehlers nicht erstellt werden.");
             }
 
             case "conf":   return await HandleReminderConf(fn, id, code);
 
             case "srs":
             {
-                if (!HasForm("id")) return BadRequest400();
+                if (!HasForm("id")) { _logger.LogWarning("Reminder srs: missing form field 'id', user={User}", UserAccountID); return BadRequest400(); }
+                _logger.LogInformation("Reminder srs: marking reminder {RemId} as sent, user={User}", Form("id"), UserAccountID);
                 var pl  = StdParamlist(SQL_VarChar("@Id", Form("id")), SQL_Bit("@auto", false));
                 var dt2 = await getSQLDataSet_async(
                     "EXECUTE [dbo].[fds__setReminderSent] @Id, @auto, @authuser;",
                     _intranet.Intranet__SQLConnectionString, pl,
                     Security: DbSec, options: SqlOpt(fn, id, code));
-                return string.IsNullOrEmpty(dt2.Exception) ? Ok() : StatusCode(500);
+                if (string.IsNullOrEmpty(dt2.Exception))
+                    await _events.ReminderMarkedSentAsync(Form("id"), Form("id"), UserAccountID);
+                else
+                {
+                    _logger.LogError("Reminder srs: SQL error marking reminder {RemId} sent: {SqlError}, user={User}", Form("id"), dt2.Exception, UserAccountID);
+                    await _events.ReminderIssueAsync(
+                        $"Mahnung {Form("id")} konnte nicht als versandt markiert werden.",
+                        UserAccountID, Form("id"));
+                }
+                return string.IsNullOrEmpty(dt2.Exception) ? await JSONAsync(new { ok = true }) : StatusCode(500);
             }
 
             case "rdoc":
             {
-                if (!HasForm("id")) return BadRequest400();
+                if (!HasForm("id")) { _logger.LogWarning("Reminder rdoc: missing form field 'id', user={User}", UserAccountID); return BadRequest400(); }
+                _logger.LogDebug("Reminder rdoc: fetching stored reminder document {RemId} typ={Typ} user={User}", Form("id"), Form("typ"), UserAccountID);
                 var (file, fc) = await _reminders.GetStoredFileAsync(Form("id"), UserAccountID, DbSec);
-                if (file == null || fc == null) return StatusCode(404, new { error = "Dokument wurde nicht gefunden" });
+                if (file == null || fc == null)
+                {
+                    _logger.LogWarning("Reminder rdoc: document not found for reminder {RemId} user={User}", Form("id"), UserAccountID);
+                    return StatusCode(404, new { error = "Dokument wurde nicht gefunden" });
+                }
                 return Form("typ") != "img"
                     ? await FileContentResultAsync(fc, file.MimeType(), file.Name)
                     : await JSONAsync(new { id = Form("id"), img = await BuildPdfImageArray(fc) });
@@ -75,15 +97,27 @@ public partial class IntranetController
             case "idoc":   return await HandleReminderIdoc(fn, id, code);
             case "resend": return await HandleReminderResend(fn, id, code);
 
+            // ── Live backend-authoritative draft editing (ADR 0006) ───────────
+            case "dopen":    return await HandleReminderDraftOpen(fn, id, code);
+            case "dstate":   return await HandleReminderDraftState(fn, id, code);
+            case "dpatch":   return await HandleReminderDraftPatch(fn, id, code);
+            case "dpreview": return await HandleReminderDraftPreview(fn, id, code);
+            case "dsave":    return await HandleReminderDraftSave(fn, id, code);
+            case "dhistory": return await HandleReminderDraftHistory(fn, id, code);
+            case "dclose":   return await HandleReminderDraftClose(fn, id, code);
+
             case "lrem":
             {
-                if (!HasForm("id")) return BadRequest400();
+                if (!HasForm("id")) { _logger.LogWarning("Reminder lrem: missing form field 'id', user={User}", UserAccountID); return BadRequest400(); }
+                _logger.LogDebug("Reminder lrem: listing reminders for invoice {InvId} user={User}", Form("id"), UserAccountID);
                 var dset = await getSQLDataSet_async(
                     "EXECUTE [dbo].[fds__lookupReminders] @InvId, @authuser;",
                     _intranet.Intranet__SQLConnectionString,
                     StdParamlist(SQL_VarChar("@InvId", Form("id"))),
                     tablenames: new[] { "ov", "rem" },
                     Security: DbSec, options: SqlOpt(fn, id, code));
+                if (!string.IsNullOrEmpty(dset.Exception))
+                    _logger.LogError("Reminder lrem: SQL error for invoice {InvId}: {SqlError}, user={User}", Form("id"), dset.Exception, UserAccountID);
                 return await JSONAsync(new
                 {
                     ov  = dset.Table("ov").FirstRow.toStringDictionary(),
@@ -91,18 +125,23 @@ public partial class IntranetController
                 });
             }
 
-            default: return Ok();
+            default:
+                _logger.LogWarning("Do_Process_Reminder: unhandled action id={Id}, user={User}", id, UserAccountID);
+                return await JSONAsync(new { ok = true });
         }
     }
 
     private async Task<IActionResult> HandleReminderConf(string fn, string id, string code)
     {
-        if (!HasForm("id")) return BadRequest400();
+        if (!HasForm("id")) { _logger.LogWarning("HandleReminderConf: missing form field 'id', user={User}", UserAccountID); return BadRequest400(); }
+        _logger.LogInformation("HandleReminderConf: finalizing reminder {RemId} user={User}", Form("id"), UserAccountID);
         var dt    = await getSQLDatatable_async(
             "EXECUTE [dbo].[fds__setReminderFinal] @Id, @authuser;",
             _intranet.Intranet__SQLConnectionString,
             StdParamlist(SQL_VarChar("@Id", Form("id"))),
             Security: DbSec, options: SqlOpt(fn, id, code));
+        if (!string.IsNullOrEmpty(dt.Exception))
+            _logger.LogError("HandleReminderConf: SQL error finalizing reminder {RemId}: {SqlError}, user={User}", Form("id"), dt.Exception, UserAccountID);
         var frdic = dt.FirstRow.toObjectDictionary();
         if (frdic.TryGetValue("IsFinal", out var isFinal) && isFinal is true)
         {
@@ -127,23 +166,43 @@ public partial class IntranetController
                     email.Trim(), "", remdoc);
                 if (sent)
                 {
+                    await _events.ReminderSentToCustomerAsync(fdRem, email.Trim(), UserAccountID);
                     var pls = StdParamlist(SQL_VarChar("@Id", remId), SQL_Bit("@auto", true));
                     await getSQLDatatable_async(
                         "EXECUTE [dbo].[fds__setReminderSent] @Id, @auto, @authuser;",
                         _intranet.Intranet__SQLConnectionString, pls,
                         Security: DbSec, options: SqlOpt(fn, id, code));
                 }
+                else
+                {
+                    _logger.LogError(
+                        "Reminder email send failed — reminderId={ReminderId} email={Email} user={User}",
+                        remId, email.Trim(), UserAccountID);
+                    await _events.ReminderIssueAsync(
+                        $"Mahnung {frdic.nz("subject").ne(remId)} konnte nicht an {email.Trim()} versandt werden.",
+                        UserAccountID, remId);
                 }
-            return Ok();
             }
-        return StatusCode(500, new { error = "Aktion war nicht erfolgreich" });
+            else if (filebyte.Length == 0)
+            {
+                _logger.LogError(
+                    "Reminder PDF render returned 0 bytes — reminderId={ReminderId} user={User}",
+                    remId, UserAccountID);
+                await _events.ReminderIssueAsync(
+                    $"Die Mahn-PDF {frdic.nz("DocumentName", "").ne($"Zahlungserinnerung_{remId}.pdf")} konnte nicht erstellt werden.",
+                    UserAccountID, remId);
+            }
+            return await JSONAsync(new { ok = true });
+        }
+        return await ReminderIssueResult("Die Mahnung konnte aufgrund eines Fehlers nicht erstellt werden.");
     }
 
     private async Task<IActionResult> HandleReminderIdoc(string fn, string id, string code)
     {
-        if (!HasForm("id") || string.IsNullOrEmpty(Form("id"))) return StatusCode(404);
+        if (!HasForm("id") || string.IsNullOrEmpty(Form("id"))) { _logger.LogWarning("HandleReminderIdoc: missing/empty form field 'id', user={User}", UserAccountID); return StatusCode(404); }
+        _logger.LogDebug("HandleReminderIdoc: reminderId={RemId} typ={Typ} create={Create} user={User}", Form("id"), Form("typ"), Form("create", "0"), UserAccountID);
         var fdRem = await _reminders.LoadReminderAsync(Form("id"), UserAccountID, DbSec);
-        if (string.IsNullOrEmpty(fdRem.Id)) return StatusCode(404, new { error = "Erinnerung wurde nicht gefunden" });
+        if (string.IsNullOrEmpty(fdRem.Id)) { _logger.LogWarning("HandleReminderIdoc: reminder not found id={RemId} user={User}", Form("id"), UserAccountID); return StatusCode(404, new { error = "Erinnerung wurde nicht gefunden" }); }
         string filename = fdRem.ReminderRegistration!.nz("DocumentName").ne($"Zahlungserinnerung_{fdRem.Id}.pdf");
         if (Form("typ") != "img")
         {
@@ -158,7 +217,8 @@ public partial class IntranetController
 
     private async Task<IActionResult> HandleReminderResend(string fn, string id, string code)
     {
-        if (!HasForm("id") || string.IsNullOrEmpty(Form("id"))) return StatusCode(404);
+        if (!HasForm("id") || string.IsNullOrEmpty(Form("id"))) { _logger.LogWarning("HandleReminderResend: missing/empty form field 'id', user={User}", UserAccountID); return StatusCode(404); }
+        _logger.LogInformation("HandleReminderResend: resending reminder {RemId} user={User}", Form("id"), UserAccountID);
         var pl = StdParamlist(SQL_VarChar("@Id", Form("id")), new SqlParameter("@includefile", true));
         var dset  = await getSQLDataSet_async(
             "EXECUTE [dbo].[fds__getReminder] @Id, @includefile, @authuser;",
@@ -178,14 +238,39 @@ public partial class IntranetController
                 if (!string.IsNullOrEmpty(frdic.nz("InvoiceFileName")) &&
                     frdic.no("InvoiceFile", null!) is byte[] invFile)
                     remdoc[frdic.nz("InvoiceFileName")] = invFile;
-                await _comService.SendEmailAsync($"rem_{remId}",
+                bool sent = await _comService.SendEmailAsync($"rem_{remId}",
                     $"SanitärFuchs - {frdic.nz("subject").ne(frdic.nz("DocumentName"))}",
                     BuildReminderBody(Convert.ToDouble(frdic.no("amount_open", 0))),
                     email.Trim(), "", remdoc);
+                if (sent)
+                {
+                    var fdRem = await _reminders.LoadReminderAsync(remId, UserAccountID, DbSec);
+                    await _events.ReminderSentToCustomerAsync(fdRem, email.Trim(), UserAccountID, resent: true);
                 }
-            return Ok();
+                else
+                {
+                    _logger.LogError(
+                        "Reminder resend email send failed — reminderId={ReminderId} email={Email} user={User}",
+                        remId, email.Trim(), UserAccountID);
+                    await _events.ReminderIssueAsync(
+                        $"Mahnung {frdic.nz("subject").ne(remId)} konnte nicht erneut an {email.Trim()} versandt werden.",
+                        UserAccountID, remId);
                 }
-        return StatusCode(500, new { error = "Aktion war nicht erfolgreich" });
+            }
+            return await JSONAsync(new { ok = true });
+        }
+        return await ReminderIssueResult("Die Mahnung konnte aufgrund eines Fehlers nicht versandt werden.");
+    }
+
+    private async Task<IActionResult> ReminderIssueResult(string message, string reminderId = "")
+    {
+        // Mirrors the SignalR toast in a durable app log: without this, a reminder
+        // save/create/send failure was only visible as a GUI notification nobody was
+        // necessarily watching at the time.
+        _logger.LogError("Reminder issue — reminderId={ReminderId} user={User} message={Message}",
+            reminderId, UserAccountID, message);
+        await _events.ReminderIssueAsync(message, UserAccountID, reminderId);
+        return StatusCode(500, new { error = message });
     }
 
     private static string BuildReminderBody(double amountOpen) =>

Fuchs/Controllers/IntranetController.ReminderDraft.cs

@@ -0,0 +1,122 @@
+using Fuchs.Services;
+using Microsoft.AspNetCore.Mvc;
+using Newtonsoft.Json;
+using Newtonsoft.Json.Linq;
+using static OCORE.web.mvc_helper_async;
+
+namespace Fuchs.Controllers;
+
+// Partial class: live, backend-authoritative reminder draft editing (ADR 0006) — the
+// reminder mirror of IntranetController.InvoiceDraft.cs. The browser posts single edits
+// here; the server mutates the in-memory session (the source of truth), recomputes the
+// open amount / validates, and pings the editing browser over the shared DraftPreviewHub
+// (draftReady) to re-fetch. Commands are ordinary POSTs — the hub carries only signals.
+public partial class IntranetController
+{
+    // POST rem/dopen — { payload } → { token, version }
+    private async Task<IActionResult> HandleReminderDraftOpen(string fn, string id, string code)
+    {
+        if (!HasForm("payload"))
+        {
+            _logger.LogWarning("Reminder draft dopen: 'payload' missing user={User}", UserAccountID);
+            return BadRequest400();
+        }
+        JObject payload;
+        try { payload = JObject.Parse(Form("payload")); }
+        catch (JsonException ex)
+        {
+            _logger.LogWarning(ex, "Reminder draft dopen: invalid payload JSON user={User}", UserAccountID);
+            return BadRequest400();
+        }
+        var session = _reminderDrafts.OpenFromPayload(payload, UserAccountID);
+        _logger.LogInformation("Reminder draft dopen: session {Token} (remId={RemId}) user={User}", session.Token, session.RemId, UserAccountID);
+        // The browser holds the token from this response and fetches dstate directly; there is
+        // no server 'draftReady' on open (it would race the client's group-join).
+        return await JSONAsync(new { token = session.Token, version = session.Version });
+    }
+
+    // POST rem/dstate — { token } → full view state
+    private async Task<IActionResult> HandleReminderDraftState(string fn, string id, string code)
+    {
+        if (!HasForm("token")) return BadRequest400();
+        var session = _reminderDrafts.Get(Form("token"));
+        if (session == null) return DraftGone();
+        return await JSONAsync(_reminderDrafts.BuildState(session));
+    }
+
+    // POST rem/dpatch — { token, delta } → { ok, version }; signals draftReady
+    private async Task<IActionResult> HandleReminderDraftPatch(string fn, string id, string code)
+    {
+        if (!HasForm("token", "delta")) return BadRequest400();
+        ReminderDraftDelta? delta;
+        try { delta = JsonConvert.DeserializeObject<ReminderDraftDelta>(Form("delta")); }
+        catch (JsonException ex)
+        {
+            _logger.LogWarning(ex, "Reminder draft dpatch: invalid delta JSON user={User}", UserAccountID);
+            return BadRequest400();
+        }
+        if (delta == null || string.IsNullOrEmpty(delta.Target)) return BadRequest400();
+
+        var session = _reminderDrafts.ApplyPatch(Form("token"), delta);
+        if (session == null) return DraftGone();
+        await _draftNotifier.SignalDraftReadyAsync(session.Token, session.Version);
+        return await JSONAsync(new { ok = true, version = session.Version });
+    }
+
+    // POST rem/dpreview — { token } → { img[], total } (rendered straight from the cache)
+    private async Task<IActionResult> HandleReminderDraftPreview(string fn, string id, string code)
+    {
+        if (!HasForm("token")) return BadRequest400();
+        var doc = _reminderDrafts.RenderPreview(Form("token"));
+        if (doc == null) return DraftGone();
+        var imgcol = await _pdf.DocToImageCollectionAsync(doc);
+        return await JSONAsync(new { img = imgcol.ImgB64Array, total = imgcol.TotalPages });
+    }
+
+    // POST rem/dsave — { token } → { ok, remid }; flush cache→DB + business event + draftReady
+    private async Task<IActionResult> HandleReminderDraftSave(string fn, string id, string code)
+    {
+        if (!HasForm("token")) return BadRequest400();
+        string token = Form("token");
+        var before = _reminderDrafts.Get(token);
+        if (before == null) return DraftGone();
+        bool existed = !string.IsNullOrEmpty(before.RemId);
+
+        var fdRem = await _reminderDrafts.FlushToDbAsync(token, UserAccountID, DbSec);
+        if (fdRem == null) return DraftGone();
+        if (string.IsNullOrEmpty(fdRem.Id))
+            return await ReminderIssueResult("Der Zwischenstand konnte aufgrund eines Fehlers nicht gespeichert werden.");
+
+        await _events.ReminderDraftRegisteredAsync(fdRem, existed, UserAccountID);
+        var after = _reminderDrafts.Get(token);
+        if (after != null) await _draftNotifier.SignalDraftReadyAsync(after.Token, after.Version);
+        return await JSONAsync(new { ok = true, remid = fdRem.Id });
+    }
+
+    // POST rem/dhistory — { token } → { history[] }
+    private async Task<IActionResult> HandleReminderDraftHistory(string fn, string id, string code)
+    {
+        if (!HasForm("token")) return BadRequest400();
+        if (_reminderDrafts.Get(Form("token")) == null) return DraftGone();
+        var history = _reminderDrafts.GetHistory(Form("token"))
+            .Select(h => new
+            {
+                timestamp = h.TimestampUtc,
+                target    = h.Target,
+                @ref      = h.Ref,
+                oldValue  = h.OldValue,
+                newValue  = h.NewValue,
+                version   = h.Version
+            });
+        return await JSONAsync(new { history });
+    }
+
+    // POST rem/dclose — { token } → { ok }
+    private async Task<IActionResult> HandleReminderDraftClose(string fn, string id, string code)
+    {
+        if (!HasForm("token")) return BadRequest400();
+        bool ok = _reminderDrafts.Close(Form("token"));
+        _logger.LogDebug("Reminder draft dclose token={Token} removed={Removed} user={User}", Form("token"), ok, UserAccountID);
+        return await JSONAsync(new { ok });
+    }
+}

Fuchs/Controllers/IntranetController.Reports.cs

@@ -36,7 +36,15 @@ public partial class IntranetController
                         ri["params"] = dset.Tables("params")
                             .toArrayofObjectDictionaries($"[object_id] = {ri["object_id"]} AND [name] <> '@authuser'");
                     }
-                    catch { ri["params"] = Array.Empty<Dictionary<string, object>>(); }
+                    catch (Exception ex)
+                    {
+                        // Without this, a genuinely broken params filter/query is indistinguishable
+                        // from the expected "this report has no params" case in the response.
+                        _logger.LogWarning(ex,
+                            "Report catalog: failed to load params for object_id={ObjectId} user={User}",
+                            ri["object_id"], UserAccountID);
+                        ri["params"] = Array.Empty<Dictionary<string, object>>();
+                    }
                 }
                 return await JSONAsync(new
                 {

Fuchs/Controllers/IntranetController.Requests.cs

@@ -27,13 +27,16 @@ public partial class IntranetController
 
             case "rthd":
             {
-                if (!HasForm("id")) return BadRequest400();
+                if (!HasForm("id")) { _logger.LogWarning("Requests rthd: missing form field 'id', user={User}", UserAccountID); return BadRequest400(); }
+                _logger.LogInformation("Requests rthd: toggling hidden state for request {ReqId}, user={User}", Form("id"), UserAccountID);
                 var sqldt = await getSQLDatatable_async(
                     "EXECUTE [dbo].[fds__toggleRequestHidden] @Id, @authuser;",
                     _intranet.Intranet__SQLConnectionString,
                     StdParamlist(SQL_BigInt("@Id", Form("id"))),
                     Security: DbSec, options: SqlOpt(fn, id, code));
-                if (sqldt.Count == 0) return StatusCode(404, new { error = "not found" });
+                if (!string.IsNullOrEmpty(sqldt.Exception))
+                    _logger.LogError("Requests rthd: SQL error for request {ReqId}: {SqlError}, user={User}", Form("id"), sqldt.Exception, UserAccountID);
+                if (sqldt.Count == 0) { _logger.LogWarning("Requests rthd: request {ReqId} not found, user={User}", Form("id"), UserAccountID); return StatusCode(404, new { error = "not found" }); }
                 var dic = sqldt.FirstRow.toObjectDictionary();
                 return await JSONAsync(new { id = dic["EntityId"], visible = dic.no("hidden", false) is not true });
             }
@@ -45,63 +48,87 @@ public partial class IntranetController
 
             case "save":
             {
-                if (!HasForm("invc")) return BadRequest400();
+                if (!HasForm("invc")) { _logger.LogWarning("Requests save: missing form field 'invc', user={User}", UserAccountID); return BadRequest400(); }
+                bool saveChange = !string.IsNullOrEmpty(Form("id"));
+                _logger.LogInformation("Requests save: saving invoice draft change={Change} invId={InvId} user={User}", saveChange, Form("id"), UserAccountID);
                 var fdInv = await _invoices.RegisterInvoiceAsync(
                     new FdsInvoiceData(JsonConvert.DeserializeObject(Form("invc"))!),
-                    change: !string.IsNullOrEmpty(Form("id")), invId: Form("id"), UserAccountID, DbSec);
+                    change: saveChange, invId: Form("id"), UserAccountID, DbSec);
+                if (!string.IsNullOrEmpty(fdInv.Id))
+                {
+                    _logger.LogInformation("Requests save: invoice draft {InvId} saved, user={User}", fdInv.Id, UserAccountID);
+                    await _events.InvoiceDraftRegisteredAsync(fdInv, saveChange, UserAccountID);
+                }
                 return !string.IsNullOrEmpty(fdInv.Id)
                     ? await JSONAsync(new { id = fdInv.Id })
-                    : StatusCode(500, new { error = "Rechnung wurde nicht gespeichert" });
+                    : await InvoiceIssueResult("Die Rechnung konnte aufgrund eines Fehlers nicht gespeichert werden.");
             }
 
             case "sprep":
             {
-                if (!HasForm("invc")) return BadRequest400();
+                if (!HasForm("invc")) { _logger.LogWarning("Requests sprep: missing form field 'invc', user={User}", UserAccountID); return BadRequest400(); }
+                _logger.LogInformation("Requests sprep: preparing new invoice draft, user={User}", UserAccountID);
                 var fdInv = await _invoices.RegisterInvoiceAsync(
                     new FdsInvoiceData(JsonConvert.DeserializeObject(Form("invc"))!),
                     change: false, invId: "", UserAccountID, DbSec);
                 if (!string.IsNullOrEmpty(fdInv.Id))
                 {
+                    _logger.LogInformation("Requests sprep: invoice draft {InvId} created, user={User}", fdInv.Id, UserAccountID);
+                    await _events.InvoiceDraftRegisteredAsync(fdInv, changed: false, userAccountId: UserAccountID);
                     var imgcol = await _pdf.DocToImageCollectionAsync(_invoices.GenerateInvoicePdf(fdInv, fdInv.IsDraft));
                     return await JSONAsync(new { id = fdInv.Id, img = imgcol.ImgB64Array, total = imgcol.TotalPages });
                 }
-                return StatusCode(500, new { error = "Rechnung wurde nicht registriert" });
+                return await InvoiceIssueResult("Die Rechnung konnte aufgrund eines Fehlers nicht erstellt werden.");
             }
 
             case "sedit":
             {
-                if (!HasForm("id", "invc")) return BadRequest400();
+                if (!HasForm("id", "invc")) { _logger.LogWarning("Requests sedit: missing form field 'id'/'invc', user={User}", UserAccountID); return BadRequest400(); }
+                _logger.LogInformation("Requests sedit: updating invoice draft {InvId}, user={User}", Form("id"), UserAccountID);
                 var fdInv = await _invoices.RegisterInvoiceAsync(
                     new FdsInvoiceData(JsonConvert.DeserializeObject(Form("invc"))!),
                     change: true, invId: Form("id"), UserAccountID, DbSec);
                 if (!string.IsNullOrEmpty(fdInv.Id))
                 {
+                    _logger.LogInformation("Requests sedit: invoice draft {InvId} updated, user={User}", fdInv.Id, UserAccountID);
+                    await _events.InvoiceDraftRegisteredAsync(fdInv, changed: true, userAccountId: UserAccountID);
                     var imgcol = await _pdf.DocToImageCollectionAsync(_invoices.GenerateInvoicePdf(fdInv, fdInv.IsDraft));
                     return await JSONAsync(new { id = fdInv.Id, img = imgcol.ImgB64Array, total = imgcol.TotalPages });
                 }
-                return StatusCode(500, new { error = "Rechnung wurde nicht registriert" });
+                return await InvoiceIssueResult("Die Rechnung konnte aufgrund eines Fehlers nicht aktualisiert werden.");
             }
 
             case "sdel":
-                if (!HasForm("id")) return BadRequest400();
-                await setSQLValue_async("EXECUTE [dbo].[fds__remInvoice] @Id, @authuser;",
+            {
+                if (!HasForm("id")) { _logger.LogWarning("Requests sdel: missing form field 'id', user={User}", UserAccountID); return BadRequest400(); }
+                _logger.LogInformation("Requests sdel: deleting invoice draft {InvId}, user={User}", Form("id"), UserAccountID);
+                var ok = await setSQLValue_async("EXECUTE [dbo].[fds__remInvoice] @Id, @authuser;",
                     _intranet.Intranet__SQLConnectionString,
                     StdParamlist(SQL_VarChar("@Id", Form("id"))),
                     Security: DbSec, options: SqlOpt(fn, id, code));
-                return Ok();
+                if (!ok)
+                {
+                    _logger.LogError("Requests sdel: SQL failed deleting invoice draft {InvId}, user={User}", Form("id"), UserAccountID);
+                    return await InvoiceIssueResult("Die Rechnung konnte aufgrund eines Fehlers nicht gelöscht werden.", Form("id"));
+                }
+                return await JSONAsync(new { ok = true });
+            }
 
             case "sconf":  return await HandleRequestSconf(fn, id, code);
             case "idoc":   return await HandleRequestIdoc(fn, id, code);
             case "resend": return await HandleRequestResend(fn, id, code);
 
-            default: return Ok();
+            default:
+                _logger.LogWarning("Do_Process_Requests: unhandled action id={Id}, user={User}", id, UserAccountID);
+                return await JSONAsync(new { ok = true });
         }
     }
 
     private async Task<IActionResult> HandleRequestList(string fn, string id, string code)
     {
-        if (!HasForm("mode")) return BadRequest400();
+        if (!HasForm("mode")) { _logger.LogWarning("HandleRequestList: missing form field 'mode', user={User}", UserAccountID); return BadRequest400(); }
         string mode = Form("mode").ToLower();
+        _logger.LogDebug("HandleRequestList mode={Mode} tgt={Tgt} user={User}", mode, Form("tgt"), UserAccountID);
         if (mode == "s" && Form("tgt").Contains(':'))
         {
             var pl = StdParamlist(
@@ -122,7 +149,10 @@ public partial class IntranetController
         }
         if (!DateTime.TryParseExact(Form("tgt"), "yy-MM-dd",
             CultureInfo.InvariantCulture, DateTimeStyles.AllowWhiteSpaces, out var tgtdate))
+        {
+            _logger.LogWarning("HandleRequestList: invalid date format tgt='{Tgt}' user={User}", Form("tgt"), UserAccountID);
             return BadRequest400();
+        }
         {
             var pl = StdParamlist(
                 SQL_Date("@tgtdate", tgtdate),
@@ -141,20 +171,33 @@ public partial class IntranetController
         }
     }
 
-    private static List<Dictionary<string, object?>> AttachReports(SQLDataSet dset)
+    private List<Dictionary<string, object?>> AttachReports(SQLDataSet dset)
     {
         var req = new List<Dictionary<string, object?>>(dset.Tables("requests").toArrayofObjectDictionaries()!);
         foreach (var r in req)
         {
             try { r["reports"] = dset.Tables("reports").toArrayofObjectDictionaries($"[requestID] = {r["Id"]}"); }
-            catch { /* no reports table */ }
+            catch (Exception ex)
+            {
+                // "reports" table absent is expected for some queries; but a real failure while
+                // joining (e.g. malformed filter) looked identical to that with no way to tell them apart.
+                _logger.LogWarning(ex,
+                    "AttachReports: failed to join reports for requestId={RequestId} user={User}",
+                    r["Id"], UserAccountID);
+            }
         }
         return req;
     }
 
     private async Task<IActionResult> HandleRequestPget(string fn, string id, string code)
     {
-        if (!HasForm("id") || !long.TryParse(Form("id"), out long tgtid)) return BadRequest400();
+        if (!HasForm("id") || !long.TryParse(Form("id"), out long tgtid))
+        {
+            _logger.LogWarning("HandleRequestPget: missing/invalid 'id' value='{Value}' user={User}", Form("id"), UserAccountID);
+            return BadRequest400();
+        }
+        _logger.LogDebug("HandleRequestPget tgtid={TgtId} user={User}", tgtid, UserAccountID);
+
         var dt = await getSQLDatatable_async(
             "SELECT * FROM [dbo].[fds__getRequestTreeIds](@srqid);",
             _intranet.Intranet__SQLConnectionString,
@@ -170,20 +213,25 @@ public partial class IntranetController
                 if (iid > 0 && !ids.Contains(iid)) ids.Add(iid);
             }
         }
+        _logger.LogDebug("HandleRequestPget tgtid={TgtId} resolved {Count} related ids: {Ids}", tgtid, ids.Count, string.Join(",", ids));
+
         var schemaDic = new Dictionary<string, fds.FdsMfrClient.DatabaseSchema>
         {
             [EntityHelper.EntityName(EntityTypes.ServiceRequest)] =
                 new fds.FdsMfrClient.DatabaseSchema(EntityTypes.ServiceRequest)
         };
         using var mfr = _mfrFactory.Create();
-        await mfr.Update__entitytable(EntityTypes.ServiceRequest,
+        bool ok = await mfr.Update__entitytable(EntityTypes.ServiceRequest,
             fds.FdsMfr.UpdateNeed.Reset, ids.ToArray(), schemaDic: schemaDic);
-        return Ok();
+        _logger.LogInformation("HandleRequestPget MFR update complete tgtid={TgtId} ids={Count} success={Success} user={User}",
+            tgtid, ids.Count, ok, UserAccountID);
+        return await JSONAsync(new { ok });
     }
 
     private async Task<IActionResult> HandleRequestGet(string fn, string id, string code)
     {
-        if (!HasForm("id")) return BadRequest400();
+        if (!HasForm("id")) { _logger.LogWarning("HandleRequestGet: missing form field 'id', user={User}", UserAccountID); return BadRequest400(); }
+        _logger.LogDebug("HandleRequestGet requestId={ReqId} mode={Mode} user={User}", Form("id"), Form("mode"), UserAccountID);
         string modeVal = Form("mode").ne("ov");
         string[] tn = modeVal switch
         {
@@ -210,7 +258,8 @@ public partial class IntranetController
 
     private async Task<IActionResult> HandleRequestIget(string fn, string id, string code)
     {
-        if (!HasForm("id", "typ")) return BadRequest400();
+        if (!HasForm("id", "typ")) { _logger.LogWarning("HandleRequestIget: missing form field 'id'/'typ', user={User}", UserAccountID); return BadRequest400(); }
+        _logger.LogDebug("HandleRequestIget requestId={ReqId} typ={Typ} mode={Mode} user={User}", Form("id"), Form("typ"), Form("mode"), UserAccountID);
         var pl = StdParamlist(
             SQL_BigInt("@servicerequestid", Form("id")),
             SQL_VarChar("@mode", Form("mode").ne("ov")),
@@ -252,12 +301,15 @@ public partial class IntranetController
 
     private async Task<IActionResult> HandleRequestSconf(string fn, string id, string code)
     {
-        if (!HasForm("id")) return BadRequest400();
+        if (!HasForm("id")) { _logger.LogWarning("HandleRequestSconf: missing form field 'id', user={User}", UserAccountID); return BadRequest400(); }
+        _logger.LogInformation("HandleRequestSconf: finalizing invoice {InvId} user={User}", Form("id"), UserAccountID);
         var dt    = await getSQLDatatable_async(
             "EXECUTE [dbo].[fds__setInvoiceFinal] @Id, @authuser;",
             _intranet.Intranet__SQLConnectionString,
             StdParamlist(SQL_VarChar("@Id", Form("id"))),
             Security: DbSec, options: SqlOpt(fn, id, code));
+        if (!string.IsNullOrEmpty(dt.Exception))
+            _logger.LogError("HandleRequestSconf: SQL error finalizing invoice {InvId}: {SqlError}, user={User}", Form("id"), dt.Exception, UserAccountID);
         var frdic = dt.FirstRow.toObjectDictionary();
         if (frdic.TryGetValue("IsFinal", out var isFinal) && isFinal is true)
         {
@@ -285,31 +337,72 @@ public partial class IntranetController
                     body, email.Trim(), "", inv);
                 if (sent)
                 {
+                    await _events.InvoiceSentToCustomerAsync(fdInv, email.Trim(), UserAccountID);
                     var pls = StdParamlist(SQL_VarChar("@Id", invId), SQL_Bit("@auto", true));
                     await getSQLDatatable_async("EXECUTE [dbo].[fds__setInvoiceSent] @Id, @auto, @authuser;",
                         _intranet.Intranet__SQLConnectionString, pls,
                         Security: DbSec, options: SqlOpt(fn, id, code));
                 }
+                else
+                {
+                    _logger.LogError(
+                        "Invoice email send failed — invoiceId={InvoiceId} email={Email} user={User}",
+                        invId, email.Trim(), UserAccountID);
+                    await _events.InvoiceIssueAsync(
+                        $"Rechnung {frdic.nz("InvoiceId").ne(invId)} konnte nicht an {email.Trim()} versandt werden.",
+                        UserAccountID, invId);
                 }
-            return Ok();
             }
-        return StatusCode(500, new { error = "Aktion war nicht erfolgreich" });
+            else if (filebyte.Length == 0)
+            {
+                _logger.LogError(
+                    "Invoice PDF render returned 0 bytes — invoiceId={InvoiceId} user={User}",
+                    invId, UserAccountID);
+                await _events.InvoiceIssueAsync(
+                    $"Die Rechnungs-PDF {frdic.nz("DocumentName").ne($"Rechnung_{invId}.pdf")} konnte nicht erstellt werden.",
+                    UserAccountID, invId);
+            }
+            // hasFile tells the frontend whether the PDF was actually stored, so it only opens the
+            // idoc preview popup when there is something to show (never on a failed render/store).
+            return await JSONAsync(new { ok = true, hasFile = filebyte.Length > 0 });
+        }
+        return await InvoiceIssueResult("Die Rechnung konnte aufgrund eines Fehlers nicht erstellt werden.");
+    }
+
+    /// <summary>
+    /// Serves the PDF inline (browser shows it) while advertising the real download filename —
+    /// both a quoted ASCII form and RFC 5987 <c>filename*</c> for spaces/non-ASCII. Works around
+    /// the OCORE FileContentResult helper, whose classic-MVC <c>ExecuteResult(ControllerContext)</c>
+    /// never runs under ASP.NET Core, so the filename was dropped and downloads used the "idoc"
+    /// endpoint segment.
+    /// </summary>
+    private void SetInlinePdfFilename(string filename)
+    {
+        string safe = (filename ?? "").Replace("\"", "").Replace("\r", " ").Replace("\n", " ").Trim();
+        if (safe.Length == 0) return;
+        Response.Headers["Content-Disposition"] =
+            $"inline; filename=\"{safe}\"; filename*=UTF-8''{Uri.EscapeDataString(safe)}";
     }
 
     private async Task<IActionResult> HandleRequestIdoc(string fn, string id, string code)
     {
-        if (!HasForm("id") || string.IsNullOrEmpty(Form("id"))) return StatusCode(404);
+        if (!HasForm("id") || string.IsNullOrEmpty(Form("id"))) { _logger.LogWarning("HandleRequestIdoc: missing/empty form field 'id', user={User}", UserAccountID); return StatusCode(404); }
+        _logger.LogDebug("HandleRequestIdoc: invoiceId={InvId} typ={Typ} create={Create} user={User}", Form("id"), Form("typ"), Form("create", "0"), UserAccountID);
         var fdInv = await _invoices.LoadInvoiceAsync(Form("id"), UserAccountID, DbSec);
-        if (string.IsNullOrEmpty(fdInv.Id)) return StatusCode(404, new { error = "Rechnung wurde nicht gefunden" });
+        if (string.IsNullOrEmpty(fdInv.Id)) { _logger.LogWarning("HandleRequestIdoc: invoice not found id={InvId} user={User}", Form("id"), UserAccountID); return StatusCode(404, new { error = "Rechnung wurde nicht gefunden" }); }
         string filename = fdInv.InvoiceRegistration!.nz("DocumentName").ne($"Rechnung_{fdInv.Id}.pdf");
         if (Form("typ") != "img")
         {
             byte[]? ct = Form("create", "0") != "1"
                 ? await _invoices.GetInvoiceFileAsync(fdInv, fdInv.IsDraft, _mfr) is { Length: > 0 } f1 ? f1 : await _invoices.StoreInvoiceDocumentFileAsync(fdInv, fdInv.IsDraft, UserAccountID, DbSec)
                 : _pdf.DocToPdfBytes(_invoices.GenerateInvoicePdf(fdInv, fdInv.IsDraft));
-            return ct != null
-                ? await FileContentResultAsync(ct, "application/pdf", filename, inline: true)
-                : StatusCode(500, new { error = "Rechnungs-PDF konnte nicht erstellt werden" });
+            if (ct == null)
+                return await InvoiceIssueResult("Die Rechnungs-PDF konnte aufgrund eines Fehlers nicht erstellt werden.", fdInv.Id);
+            // Serve inline for the in-browser viewer, but carry the real DocumentName so the browser's
+            // "download" uses "Rechnung R2026-0121.pdf" instead of the "idoc" endpoint segment. (The
+            // OCORE FileContentResult helper drops the filename under ASP.NET Core, so set it here.)
+            SetInlinePdfFilename(filename);
+            return File(ct, "application/pdf");
         }
         var imgcol = await _pdf.DocToImageCollectionAsync(_invoices.GenerateInvoicePdf(fdInv, fdInv.IsDraft));
         return await JSONAsync(new { id = fdInv.Id, img = imgcol.ImgB64Array, total = imgcol.TotalPages });
@@ -317,7 +410,8 @@ public partial class IntranetController
 
     private async Task<IActionResult> HandleRequestResend(string fn, string id, string code)
     {
-        if (!HasForm("id") || string.IsNullOrEmpty(Form("id"))) return StatusCode(404);
+        if (!HasForm("id") || string.IsNullOrEmpty(Form("id"))) { _logger.LogWarning("HandleRequestResend: missing/empty form field 'id', user={User}", UserAccountID); return StatusCode(404); }
+        _logger.LogInformation("HandleRequestResend: resending invoice {InvId} user={User}", Form("id"), UserAccountID);
         var dtset = await getSQLDataSet_async(
             "EXECUTE [dbo].[fds__getInvoice] @Id, @authuser;",
             _intranet.Intranet__SQLConnectionString,
@@ -335,14 +429,35 @@ public partial class IntranetController
             {
                 double bal   = Convert.ToDouble(frdic.no("InvoiceBalance", 0));
                 string terms = fdInv.PaymentTerms.Replace("wd", " Werktagen").Replace("d", " Tagen").Replace("wk", " Wochen").ne("10 Tagen");
-                await _comService.SendEmailAsync(
+                bool sent = await _comService.SendEmailAsync(
                     $"inv_{invId}", $"Sanit\u00e4rFuchs - {frdic.nz("DocumentName")}",
                     BuildInvoiceBody(bal, terms), email.Trim(), "",
                     new Dictionary<string, byte[]> { [frdic.nz("DocumentName")] = filebyte });
+                if (sent)
+                    await _events.InvoiceSentToCustomerAsync(fdInv, email.Trim(), UserAccountID, resent: true);
+                else
+                {
+                    _logger.LogError(
+                        "Invoice resend email send failed — invoiceId={InvoiceId} email={Email} user={User}",
+                        invId, email.Trim(), UserAccountID);
+                    await _events.InvoiceIssueAsync(
+                        $"Rechnung {frdic.nz("InvoiceId").ne(invId)} konnte nicht erneut an {email.Trim()} versandt werden.",
+                        UserAccountID, invId);
                 }
-            return Ok();
             }
-        return StatusCode(500, new { error = "Aktion war nicht erfolgreich" });
+            return await JSONAsync(new { ok = true });
+        }
+        return await InvoiceIssueResult("Die Rechnung konnte aufgrund eines Fehlers nicht versandt werden.");
+    }
+
+    private async Task<IActionResult> InvoiceIssueResult(string message, string invoiceId = "")
+    {
+        // Mirrors the SignalR toast in a durable app log: without this, an invoice save/create/send
+        // failure was only visible as a GUI notification nobody was necessarily watching at the time.
+        _logger.LogError("Invoice issue — invoiceId={InvoiceId} user={User} message={Message}",
+            invoiceId, UserAccountID, message);
+        await _events.InvoiceIssueAsync(message, UserAccountID, invoiceId);
+        return StatusCode(500, new { error = message });
     }
 
     private static string BuildInvoiceBody(double balance, string paymentTerms) =>

Fuchs/Controllers/IntranetController.cs

@@ -1,5 +1,6 @@
 using System.Web;
 using Fuchs.intranet;
+using Fuchs.Notifications;
 using Fuchs.Services;
 using Microsoft.AspNetCore.Authentication;
 using Microsoft.AspNetCore.Authorization;
@@ -33,6 +34,11 @@ public partial class IntranetController : Microsoft.AspNetCore.Mvc.Controller
     private readonly IReportService _reports;
     private readonly IInvoiceService _invoices;
     private readonly IReminderService _reminders;
+    private readonly IEventService _events;
+    private readonly IInvoiceDraftService _invoiceDrafts;
+    private readonly IReminderDraftService _reminderDrafts;
+    private readonly IDraftNotifier _draftNotifier;
+    private readonly ISystemStatusService _systemStatus;
     private readonly List<string> _allowedNonAuth = new() { "spwc", "spw" };
     private readonly List<string> _allowedGet = new()
     {
@@ -59,7 +65,12 @@ public partial class IntranetController : Microsoft.AspNetCore.Mvc.Controller
         IWidgetService widgets,
         IReportService reports,
         IInvoiceService invoices,
-        IReminderService reminders)
+        IReminderService reminders,
+        IEventService events,
+        IInvoiceDraftService invoiceDrafts,
+        IReminderDraftService reminderDrafts,
+        IDraftNotifier draftNotifier,
+        ISystemStatusService systemStatus)
     {
         _intranet = intranet;
         _mfr = mfr;
@@ -72,6 +83,11 @@ public partial class IntranetController : Microsoft.AspNetCore.Mvc.Controller
         _reports = reports;
         _invoices = invoices;
         _reminders = reminders;
+        _events = events;
+        _invoiceDrafts = invoiceDrafts;
+        _reminderDrafts = reminderDrafts;
+        _draftNotifier = draftNotifier;
+        _systemStatus = systemStatus;
     }
 
     /// <summary>Merged query-string + form parameters (form wins) for report processing.</summary>
@@ -102,7 +118,7 @@ public partial class IntranetController : Microsoft.AspNetCore.Mvc.Controller
     public DatabaseSecurity DbSec => _intranet.GetDbSecurity(UserAccountID);
 
     public FIS_SQLOptions SqlOpt(string fn, string id, string code) =>
-        new(new Dictionary<string, object> { ["fn"] = fn, ["id"] = id, ["code"] = code });
+        new(new Dictionary<string, object> { ["fn"] = fn, ["id"] = id, ["code"] = code }, _logger);
 
     // ── Action helpers ────────────────────────────────────────────────────────
     protected IActionResult Unauthorized401()  => StatusCode(401);
@@ -140,7 +156,7 @@ public partial class IntranetController : Microsoft.AspNetCore.Mvc.Controller
         {
             IActionResult? result = fn.ToLower() switch
             {
-                "ping"    => Ok(),
+                "ping"    => await JSONAsync(new { ok = true }),
                 "wdg"     => await _widgets.GetWidgetAsync(id, UserAccountID, DbSec, Request),
                 "todos"   => new PhysicalFileResult(
                                  Path.Combine(Directory.GetCurrentDirectory(), "Data", "ProjectToDos.html"),
@@ -150,6 +166,7 @@ public partial class IntranetController : Microsoft.AspNetCore.Mvc.Controller
                 "rem"     => await Do_Process_Reminder(fn, id, code),
                 "rep"     => await Do_Process_Reports(fn, id, code),
                 "bam"     => await Do_Process_Bankings(fn, id, code),
+                "admin"   => await Do_Process_Admin(fn, id, code),
                 "auth"    => await HandleAuth(fn, id, code),
                 "spwc"    => await HandleSendPasswordCode(fn, id, code),
                 "spw"     => await HandleSendPassword(fn, id, code),
@@ -164,12 +181,25 @@ public partial class IntranetController : Microsoft.AspNetCore.Mvc.Controller
                 _logger.LogWarning("No handler matched fn={Fn}", fn);
             else
                 _logger.LogDebug("Do completed fn={Fn}/{Id} result={ResultType}", fn, id, result.GetType().Name);
-            return result ?? Ok();
+            return result ?? await JSONAsync(new { ok = true });
         }
         catch (Exception ex)
         {
             _logger.LogError(ex, "Unhandled exception in Do fn={Fn} id={Id} code={Code} user={User}",
                 fn, id, code, UserAccountID);
+            // Standing rule: an exception that interrupts a user-initiated action must reach the
+            // user as a notification, not only the log. This is the catch-all safety net for any
+            // Do_Process_* action that throws without first publishing its own (more specific)
+            // issue event. Pre-auth flows (login/logout, unauthenticated GETs) are skipped — there
+            // is no user session to notify and the HTTP status already conveys the failure.
+            if (UserIdent.IsAuthenticated)
+            {
+                await _events.UserIssueAsync(
+                    "Aktion fehlgeschlagen",
+                    "Die Aktion konnte aufgrund eines unerwarteten Fehlers nicht abgeschlossen werden. Bitte versuchen Sie es erneut.",
+                    UserAccountID,
+                    new Dictionary<string, object?> { ["fn"] = fn });
+            }
             return ServerError();
         }
     }
@@ -251,7 +281,7 @@ public partial class IntranetController : Microsoft.AspNetCore.Mvc.Controller
             UserAccountID, HttpContext.Connection.RemoteIpAddress);
         await HttpContext.SignOutAsync(Fuchs_intranet.AuthScheme);
         _logger.LogDebug("Logout sign-out complete for user={User}", UserAccountID);
-        return Ok();
+        return await JSONAsync(new { ok = true });
     }
 
     // ── Password helpers ──────────────────────────────────────────────────────
@@ -281,7 +311,7 @@ public partial class IntranetController : Microsoft.AspNetCore.Mvc.Controller
         {
             _logger.LogDebug("HandleSendPasswordCode: no SMS sent for email={Email} (user not found, name mismatch, no mobile, or localhost)", email);
         }
-        return Ok(); // always OK to prevent enumeration
+        return await JSONAsync(new { ok = true }); // always OK to prevent enumeration
     }
 
     private async Task<IActionResult> HandleSendPassword(string fn, string id, string code)
@@ -319,7 +349,7 @@ public partial class IntranetController : Microsoft.AspNetCore.Mvc.Controller
         {
             _logger.LogWarning("HandleSendPassword: TOTP verification failed for email={Email}", email);
         }
-        return Ok();
+        return await JSONAsync(new { ok = true });
     }
 
     private async Task<IActionResult> HandleAccount(string fn, string id, string code)
@@ -341,7 +371,7 @@ public partial class IntranetController : Microsoft.AspNetCore.Mvc.Controller
                 {
                     _logger.LogDebug("HandleAccount sms: no SMS sent for user={User} (no mobile or localhost)", UserAccountID);
                 }
-                return Ok();
+                return await JSONAsync(new { ok = true });
 
             case "changepassword":
                 string? npw  = Request.Form["npw"];
@@ -396,10 +426,10 @@ public partial class IntranetController : Microsoft.AspNetCore.Mvc.Controller
                     },
                     Security: DbSec, options: SqlOpt(fn, id, code));
                 _logger.LogDebug("Password changed successfully for user={User}", UserAccountID);
-                return Ok();
+                return await JSONAsync(new { ok = true });
         }
         _logger.LogWarning("HandleAccount unknown action={Action} user={User}", id, UserAccountID);
-        return Ok();
+        return await JSONAsync(new { ok = true });
     }
 
     private async Task<IActionResult> HandleMfr(string fn, string id, string code)
@@ -425,7 +455,7 @@ public partial class IntranetController : Microsoft.AspNetCore.Mvc.Controller
         }
         _logger.LogWarning("HandleMfr access denied for user={User} authorization={Auth}",
             UserAccountID, UserIdent.Authorization);
-        return Ok();
+        return await JSONAsync(new { ok = true });
     }
 
     private async Task<IActionResult> HandleMfrUpdate(string fn, string id, string code)
@@ -440,7 +470,7 @@ public partial class IntranetController : Microsoft.AspNetCore.Mvc.Controller
             using var mfrSingle = _mfrFactory.Create();
             await mfrSingle.Update__entitytable(et, fds.FdsMfr.UpdateNeed.Short);
             _logger.LogDebug("MfrUpdate Short completed for entity={EntityType}", et);
-            return Ok();
+            return await JSONAsync(new { ok = true });
         }
         if (et != EntityTypes.none && !string.IsNullOrEmpty(Request.Form["need"]))
         {
@@ -449,7 +479,7 @@ public partial class IntranetController : Microsoft.AspNetCore.Mvc.Controller
             using var mfr = _mfrFactory.Create();
             await mfr.Update__entitytable(et, updateNeed: need, debugDetails: false);
             _logger.LogDebug("MfrUpdate completed for entity={EntityType} need={Need}", et, need);
-            return Ok();
+            return await JSONAsync(new { ok = true });
         }
         _logger.LogWarning("HandleMfrUpdate bad request: unknown type={Type} user={User}", typeParam, UserAccountID);
         return BadRequest400();

Fuchs/Controllers/RequestValueHelper.cs

@@ -0,0 +1,21 @@
+using Microsoft.AspNetCore.Http;
+
+namespace Fuchs.Controllers;
+
+/// <summary>
+/// Resolves a request value from the posted form, falling back to the query string.
+/// Extracted as pure/testable logic: endpoints in <c>_allowedGet</c> (e.g. req/idoc, rem/idoc)
+/// are invoked via a plain GET (window.open with '?id=...'), where <see cref="HttpRequest.Form"/>
+/// has no Content-Type and throws <see cref="InvalidOperationException"/> if read directly.
+/// </summary>
+internal static class RequestValueHelper
+{
+    internal static string? Resolve(bool hasFormContentType, IFormCollection form, IQueryCollection query, string key)
+    {
+        if (hasFormContentType && form.TryGetValue(key, out var formValue))
+            return formValue.ToString();
+        if (query.TryGetValue(key, out var queryValue))
+            return queryValue.ToString();
+        return null;
+    }
+}

Fuchs/Docs/ARCHITECTURE.md

@@ -12,7 +12,7 @@ The **Fuchs Intranet** solution is a line-of-business web application for **Seba
 | Project | Type | Purpose |
 |---|---|---|
 | **Fuchs** | ASP.NET Core Web (MVC) | Main web application — the intranet |
-| **Fuchs_DataService** | Console / Windows Service (Topshelf) | Background data sync service (MFR ERP polling) |
+| **Fuchs_DataService** | Class Library | MFR ERP sync logic (entity polling, invoice/DATEV files). Hosted in-process by **Fuchs** as a `PeriodicHostedService` (see ADR 0010) — no longer a standalone process. |
 | **MFR_RESTClient** | Class Library | REST/OData client for the MFR ERP system. The REST/OData contract is documented in `MFR_RESTClient/Docs/mfr_interface_description.md`. |
 | **Fuchs_Database** | SSDT (SQL project) | Source of truth for the `fuchs_fds` SQL schema (tables, table types, functions, stored procedures the backend calls). |
 | **OCORE** | Class Library (shared) | Core utilities: SQL, crypto, email, IO, logging |
@@ -96,17 +96,18 @@ The **Fuchs Intranet** solution is a line-of-business web application for **Seba
          │                │
          ▼                ▼
 ┌─────────────────────────────────────────────────────────────────────────┐
-│                    Fuchs_DataService  (Windows Service / Console)        │
+│           Fuchs_DataService  (Class Library, hosted in-process)         │
 │                                                                         │
-│  FdsMain.cs            — Topshelf host, job definitions                 │
-│  PeriodicHostedService — BackgroundService with PeriodicTimer            │
+│  PeriodicHostedService — in Fuchs/Services; BackgroundService +         │
+│                          PeriodicTimer, registered in Program.cs         │
+│                          when Fds:SyncEnabled (ADR 0010)                 │
 │  FdsMfr.cs (IFdsMfr)  — MFR sync orchestration                         │
 │  FdsMfrClient.cs       — MFR REST client wrapper                        │
-│  FdsShared.cs          — FdsConfig (appsettings.json reader)            │
-│  FdsZip.cs             — 7-Zip archive handling (DATEV export)          │
+│  FdsShared.cs          — FdsConfig (reads the host's IConfiguration)    │
+│  (DATEV zip)           — OCORE.zip (System.IO.Compression), no 7-Zip    │
 │  FdsDebug.cs           — Debug/file logging                             │
 │                                                                         │
-│  Jobs:  MfrSync (every N min)                                           │
+│  Jobs:  MfrSync (every Fds:ExecutionFrequency_Minutes)                  │
 │    → UpdateIfNecessary_async  (entity table sync)                       │
 │    → UpdateRequested_async   (on-demand entity refresh)                 │
 │    → GetInvoiceFiles_async   (invoice PDF download)                     │
@@ -167,8 +168,14 @@ OCORE_Charting  (standalone — referenced by solution but no direct project ref
 
 ### 4.3 Service Layer (Dependency Injection)
 Business logic lives in **DI-registered services** under `Fuchs/Services/` behind interfaces, injected into `IntranetController`:
-`IComService`, `IPdfService`, `IInvoiceService`, `IReminderService`, `IReportService`, `IWidgetService`, `IBankingService`, `IMfrClientFactory`.
+`IComService`, `IPdfService`, `IInvoiceService`, `IReminderService`, `IReportService`, `IWidgetService`, `IBankingService`, `IMfrClientFactory`, `ISystemStatusService`, `IERechnungService`.
+
+`IERechnungService` (singleton) maps a finalized invoice to the EN 16931 model and embeds the
+CII XML into the render-only visual PDF to produce a ZUGFeRD/Factur-X **PDF/A-3** hybrid via the
+`eRechnungLib` submodule (gated by `Fuchs:ERechnung:Enabled`; falls back to the plain PDF/A on
+disable/failure). See [`Concepts/erechnung-output.md`](Concepts/erechnung-output.md) and ADR 0012.
 Stateless services (`IPdfService`, `IBankingService`, `IMfrClientFactory`) are singletons; DB/request-scoped services are scoped (see `Program.cs`).
+The **Admin** module (`Do_Process_Admin`, `ISystemStatusService`) surfaces a live system-status/diagnostics page (host, SQL/Key Vault/blob/MFR connectivity, email config, test-email) restricted to `fds_sys` > 4 — see ADR [0011](Decisions/0011-admin-module-system-status.md) and the [concept doc](Concepts/admin-system-status.md).
 `FdsInvoiceData` / `FdsReminderData` are now **pure data holders** (parse + properties); loading, persistence and PDF generation live in the services (fully async — no `Task.Run(...).Wait()`).
 `FuchsPdf` / `FuchsVisualization` remain as static rendering libraries used *by* the services. The earlier static, controller-coupled helpers (`FuchsWidgets`, `FuchsReports`, `Banking`, `FuchsFdsEmail`) have been removed.
 
@@ -176,7 +183,7 @@ Stateless services (`IPdfService`, `IBankingService`, `IMfrClientFactory`) are s
 There is no ORM (no EF Core). All data access uses **ADO.NET via OCORE SQL helpers** (`getSQLDatatable_async`, `getSQLDataSet_async`, `setSQLValue_async`) calling stored procedures and inline SQL. `DataTable`/`DataRow` is the primary data transfer mechanism.
 
 ### 4.5 Background Service
-`Fuchs_DataService` runs as a Windows Service (Topshelf) with a `PeriodicHostedService` that polls the MFR ERP system on a timer, syncing entities and downloading invoice files.
+The MFR ERP sync runs **in-process inside the web app** as a `PeriodicHostedService` (`Fuchs/Services/PeriodicHostedService.cs`), registered in `Program.cs` when `Fds:SyncEnabled` is true. It polls the MFR ERP on a timer (`Fds:ExecutionFrequency_Minutes`), syncing entities and downloading invoice files via the sync logic in the `Fuchs_DataService` library. See ADR [0010](Decisions/0010-mfr-sync-hosted-in-web-app.md).
 
 ### 4.6 Authentication
 Cookie-based authentication (`CookieAuthenticationDefaults`) with custom claims (`FuchsUserIdentity`). SQL-based user/password verification.
@@ -409,7 +416,7 @@ public class MfrClientFactory : IMfrClientFactory, IDisposable
 2. ✅ **Resolved** — `FdsInvoiceData`/`FdsReminderData` are now pure data holders; DB + PDF logic moved to `IInvoiceService`/`IReminderService`.
 3. ✅ **Resolved** — `FdsMfrClient` is created via `IMfrClientFactory` (no `new` in controllers).
 4. ✅ **Resolved** — `OCORE_Charting` is now used (transitively, via `OCORE_web`'s chart engine) by the report renderer (`FuchsVisualization`).
-5. ⏳ **Open** — **Topshelf** in `Fuchs_DataService` could be replaced with native `dotnet` Worker Service hosting for .NET 10 alignment.
+5. ✅ **Resolved** — **Topshelf** removed; `Fuchs_DataService` is now a class library and the MFR sync is hosted in-process by the web app as a `PeriodicHostedService` (ADR 0010).
 
 ---
 

Fuchs/Docs/Concepts/README.md

@@ -0,0 +1,66 @@
+# Concepts
+
+This folder holds **living design write-ups** of how a subsystem currently
+works: its moving parts, data flow, and how they fit together. Unlike
+[`../Decisions`](../Decisions/README.md), concept docs are **not** immutable
+— keep them in sync with the implementation as it evolves.
+
+## What belongs here
+
+"How does the notification pipeline work end to end" is a concept doc. "Why
+did we choose SignalR over polling for it" is a decision. A single feature
+area typically has one concept doc and may reference several decisions that
+shaped it.
+
+## File naming
+
+`kebab-case-topic.md` (no numbering — concepts aren't sequential events).
+
+## Required YAML frontmatter
+
+```yaml
+---
+status: Active            # Active | Deprecated
+lastUpdated: 2026-07-03
+applyTo:                  # glob(s) — files/areas this concept describes
+  - "Fuchs/Notifications/**"
+relatedDecisions:         # filenames in ../Decisions this concept implements
+  - "0001-domain-events-and-notification-triggers.md"
+---
+```
+
+**Agents must scan the YAML frontmatter of every file in this folder first**
+and only read the full body of concepts whose `applyTo` glob matches the
+files they're about to touch, or whose subject is otherwise clearly relevant.
+
+## Body template
+
+```markdown
+# Topic
+
+## Summary
+One paragraph: what this subsystem does and why it exists.
+
+## How it works
+The mechanics — components, data flow, sequencing. Diagrams (ASCII/mermaid)
+welcome where they clarify.
+
+## Key files
+Bullet list of the primary files/classes involved.
+
+## Related decisions
+Links to the ADRs in `../Decisions` that shaped this design.
+```
+
+## Rules
+
+- **Keep concepts current.** When you materially change how a documented
+  subsystem works, update its concept doc in the same change — don't let it
+  drift from the code.
+- **Create a concept doc for new non-trivial subsystems.** If you build
+  something a future agent would need a paragraph of context to safely
+  modify, write that paragraph here instead of making them re-derive it from
+  the diff.
+- Concepts describe **current** behavior. If something changes, edit the
+  doc in place — don't append a changelog inside it (git history is the
+  changelog).

Fuchs/Docs/Concepts/admin-system-status.md

@@ -0,0 +1,97 @@
+---
+status: Active
+lastUpdated: 2026-07-16
+applyTo:
+  - "Fuchs/Controllers/IntranetController.Admin.cs"
+  - "Fuchs/Services/SystemStatusService.cs"
+  - "Fuchs/Services/ISystemStatusService.cs"
+  - "Fuchs/Services/SystemStatusModels.cs"
+  - "Fuchs/js/intranet/modules/fis.admin*.js"
+  - "Fuchs/js/intranet/modules/fis.admin.scss"
+  - "Fuchs/js/intranet/fis_main_menu.js"
+relatedDecisions:
+  - "0011-admin-module-system-status.md"
+---
+
+# Admin / System-Status module
+
+## Summary
+The **Admin** module gives a privileged operator a live, in-app view of the running
+deployment's configuration and health, plus a test-email tool. It answers "which host am I
+on, can this instance reach SQL Server / Key Vault / Blob Storage / the MFR ERP, how is
+email wired up (including the OverrideRecipient redirect), and does sending actually work".
+Access is restricted to users whose `fds_sys` module authorization is greater than 4.
+
+## How it works
+
+### Authorization (two layers)
+1. **Menu visibility** — at page load `fis_main_menu.js#addAdminMenuIfAuthorized` calls
+   `$fis.getAuth('fds_sys')`; only when the level is > 4 does it push the `init:admin`
+   button into `$ocms.ocmsmenu` and re-render `#mainmenu`. Users below the threshold never
+   see the button and never fetch the module script.
+2. **Server-side gate** — every `/do/admin/*` endpoint resolves
+   `fis_getModuleAuth('fds_sys', authuser)` and returns 401 unless it is > 4. The only
+   exception is `admin/auth`, which returns `{ manage: 0 }` for unauthorized users so the
+   frontend can cleanly decline to render. This is defense in depth: hiding the button is
+   not a security control on its own.
+
+### Request flow
+```
+click "Administration"  → $ocms.init('admin')
+  POST /do/admin/auth   → { manage, level }         (manage>0 ⇒ authorized)
+  load /web/fis.admin.de.js + /web/fis.admin.css
+  $ocms.admin.init2()   → init3() renders the page
+    POST /do/admin/status → { info, probes }         full snapshot + all probes
+  per-card "Aktualisieren" → POST /do/admin/probe/<component> → { probe }
+  "Test-E-Mail senden"     → POST /do/admin/testmail (to/subject/body) → { result }
+```
+
+### Backend (`ISystemStatusService` / `SystemStatusService`, scoped)
+- `GetInfo()` — passive snapshot, no network calls: host (machine/OS/framework/environment/
+  test-deployment/uptime), database (server/catalog/login parsed from the connection string —
+  **never the password**), email (mailer enabled/base-url/account/server-id/token-present +
+  OverrideRecipient), blob (enabled/configured/containers), MFR (host/creds-present/sync),
+  Key Vault (vault-uri/app-prefix/managed-secret-count/client-registered).
+- Probes (`database`, `keyvault`, `blob`, `mfr`) each return a `SystemProbeResult`
+  (`status` = `ok`/`error`/`disabled`/`unconfigured`, `ok`, `message`, `detail`, `durationMs`,
+  optional `metrics`). They never throw — failures are captured in the result. `database` runs
+  `SELECT @@SERVERNAME, DB_NAME(), SUSER_SNAME()`; `keyvault` reads the first managed secret via
+  the DI `SecretClient`; `blob` calls `IBlobStorageService.CheckConnectivityAsync` (account-info
+  request **plus a per-container blob count** for the invoice/reminder containers, surfaced as
+  `metrics` and totalled in the message); `mfr` calls `IMfrClientFactory.Create().GetEntities()`.
+  The generic `metrics` (label/value pairs) is how a probe reports extra facts for display — the
+  blob probe uses it for the file counts.
+- `SendTestEmailAsync(to, subject, body)` HTML-encodes the body and sends via `IComService`, so
+  the `Fuchs:Email:OverrideRecipient` redirect applies exactly as for any other mail; the result
+  reports the requested recipient and, when active, the override target.
+- Every probe emits the `fuchs.systemstatus.probes` counter tagged by component + status and an
+  `systemstatus.probe` activity span.
+
+### Startup-checks widget (non-refreshable)
+`StartupSelfTestService` runs the boot self-test once (Key Vault / Database / MFR / PDF-license /
+mailer, gated by `Fuchs:StartupChecks:*`). It now also writes its outcome to the singleton
+`StartupCheckReporter`, which `GetInfo()` returns as `StartupChecks`. The Admin page renders it as a
+single **non-refreshable** card (there is no per-check retry — the live connectivity probes above
+cover on-demand re-testing; the startup card is a historical record of the boot run). When the
+self-test is disabled (`Enabled=false`, the appsettings default) or has not completed, the card shows
+a "nicht ausgeführt" note. Each item shows OK / Fehler / übersprungen (a disabled check reports
+`enabled=false`).
+
+### Frontend (`fis.admin.js` + `fis.admin_txt_de.js` + `fis.admin.scss`)
+Standard lazy-loaded module (same contract as `inv`/`rep`/`bam`). Renders a system card plus a
+responsive grid of status cards; connectivity cards carry a colored status pill and a per-card
+refresh button, the email card carries the test-email dialog. The topbar has an "Alle prüfen"
+button that reloads the whole snapshot. Admin responses are serialized **camelCase** (the DTOs are
+PascalCase) so the JS reads `probe.status`, `info.database.server`, etc.
+
+## Key files
+- `Fuchs/Controllers/IntranetController.Admin.cs` — `Do_Process_Admin` dispatch + auth gate + camelCase JSON helper.
+- `Fuchs/Services/ISystemStatusService.cs`, `SystemStatusService.cs`, `SystemStatusModels.cs` — diagnostics service + DTOs.
+- `Fuchs/Services/StartupCheckReport.cs` (`StartupCheckReporter` singleton) + `StartupSelfTestService.cs` — boot self-test result captured for the non-refreshable widget.
+- `Fuchs/Services/IBlobStorageService.cs` / `AzureBlobStorageService.cs` — `CheckConnectivityAsync` + `BlobConnectivity`.
+- `Fuchs/js/intranet/modules/fis.admin*.js`, `fis.admin.scss` — the module, texts, styles (bundled via `bdlconfig.json`).
+- `Fuchs/js/intranet/fis_main_menu.js` (`addAdminMenuIfAuthorized`) + `fis_main_go.js` — conditional menu button.
+- `Fuchs.Tests/SystemStatusServiceTests.cs` — service tests.
+
+## Related decisions
+- [0011 — Admin module gated on `fds_sys` > 4](../Decisions/0011-admin-module-system-status.md)

Fuchs/Docs/Concepts/erechnung-output.md

@@ -0,0 +1,84 @@
+---
+status: Active
+lastUpdated: 2026-07-18
+applyTo:
+  - "Fuchs/Services/ERechnungMapper.cs"
+  - "Fuchs/Services/ERechnungService.cs"
+  - "Fuchs/Services/ERechnungSettings.cs"
+  - "Fuchs/Services/InvoiceRecipientAddress.cs"
+  - "Fuchs/Services/InvoiceService.cs"
+  - "Fuchs/code/FuchsPdf.cs"
+  - "eRechnungLib/**"
+relatedDecisions:
+  - "0005-pdf-generation-and-erechnung.md"
+  - "0012-erechnung-single-pdfa-engine-pipeline.md"
+---
+
+# eRechnung output (ZUGFeRD/Factur-X)
+
+## Summary
+Finalized invoices are emitted as a **ZUGFeRD 2.4 / Factur-X** hybrid: the FuchsPdf visual PDF
+with the EN 16931 **CII XML** embedded, in a formally conformant **PDF/A-3**. This makes invoices
+DATEV-ingestible and satisfies the B2B/B2G e-invoicing mandate. The library doing the structured
+XML + PDF/A-3 work is the `eRechnungLib` submodule; Fuchs supplies the invoice data and the visual
+PDF.
+
+## How it works
+
+```
+Editor (structured recipient dialog)
+   → InvoiceDraftEditService  (address delta = JSON object, stored in CustomValues.sendToAddress)
+   → fds__setInvoice/…        (persisted; dedicated SendToAddressJson column + composed SendToAddress)
+   → InvoiceService.RenderInvoicePdfBytesAsync(final)
+        ├─ FuchsPdf.DocToPdfBytesRaw(doc)          → visual PDF (no Spire PDF/A)
+        └─ IERechnungService.TryBuildHybridPdf
+               ├─ ERechnungMapper.BuildEInvoice     FdsInvoiceData → eRechnungLib.Model.Invoice
+               └─ EInvoice.ToZugferd(EN16931, raw)  → PDF/A-3 + Factur-X hybrid (bundled sRGB ICC)
+```
+
+- **Single PDF/A engine (ADR 0012).** eRechnungLib owns the one PDF/A-3 layer. For the eRechnung
+  path the Spire PDF/A step is skipped (`DocToPdfBytesRaw`); Spire stays only for on-screen preview
+  rasterisation. This avoids a conflicting second output intent / `pdfaid` marker.
+- **Structured recipient address.** `InvoiceRecipientAddress` holds the EN 16931 buyer fields
+  (name, street, post code, city, country BT-55, optional VAT id BT-48). It is edited via a
+  dialog form (`$inv.eAddress` in `fis.inv_shared.js`), prefilled from `fds__prepInvoice`'s
+  `invoiceaddressData`, and carried as a JSON object through the draft cache. A private person
+  (no VAT id) is fully valid — B2C stays effortless. The free-text `SendToAddress` is composed
+  from it so the PDF layout is unchanged.
+- **Mapping.** `ERechnungMapper` maps the Fuchs invoice to the EN 16931 model: seller = Fuchs
+  (from `Fuchs:ERechnung:Seller` config — name, address, Steuernummer BT-32, **USt-IdNr BT-31**,
+  IBAN/BIC, contact; defaults mirror the FuchsPdf letterhead), buyer = the structured recipient,
+  lines from the invoice items, §13b → reverse charge (category AE + exemption reason), payment
+  terms BT-20/BT-9, and the service date/period (BT-72 or BG-14) parsed from the structured
+  `ProvisionPeriod`. VAT breakdown and totals are recomputed by the library.
+- **Profile selection (B2B/B2C vs B2G).** Default is ZUGFeRD **EN 16931** (DATEV). When the
+  recipient carries a **Leitweg-ID** (`InvoiceRecipientAddress.LeitwegId` → `BuyerReference` BT-10),
+  the invoice is B2G and emitted as **XRechnung** (`ZugferdProfile.XRechnung`, embedded
+  `xrechnung.xml`); the mapper then also fills the seller electronic address/contact (BT-34/BG-6)
+  and buyer electronic address (BT-49) that XRechnung requires.
+- **Feature flag & fallback.** Emission is gated by `Fuchs:ERechnung:Enabled` (off until fully
+  validated). `IERechnungService` returns `null` on disable **or any failure**, so
+  `RenderInvoicePdfBytesAsync` falls back to the plain Spire PDF/A — invoicing never breaks.
+- **Formal verification.** `Fuchs:ERechnung:Validation` calls the ProcessWeb eInvoice service
+  (`POST {ServiceUrl}/validatepdf`, raw `application/pdf`) which checks the EN 16931 XML **and**
+  PDF/A-3 (veraPDF) in one call. Both the EN 16931-ZUGFeRD and the XRechnung 3.0 output are
+  externally **ACCEPTED** (0 errors) and **PDF/A-3B COMPLIANT**. Getting there required fixing two
+  eRechnungLib defects (CII root children must be `rsm:` not `ram:`; embedded-file `/Subtype` MIME
+  encoding) and completing the mapper (seller VAT id BT-31, payment terms BT-20/BT-9). The
+  validator's target feature scope is documented in
+  [`../eRechnung-Validator-Requirements.md`](../eRechnung-Validator-Requirements.md).
+
+## Key files
+- `Fuchs/Services/InvoiceRecipientAddress.cs` — structured buyer address, composition, conformity.
+- `Fuchs/Services/ERechnungMapper.cs` — `FdsInvoiceData` → `eRechnungLib.Model.Invoice`.
+- `Fuchs/Services/ERechnungService.cs` / `ERechnungSettings.cs` — hybrid production + config.
+- `Fuchs/Services/InvoiceService.cs` — wiring in `RenderInvoicePdfBytesAsync`.
+- `Fuchs/code/FuchsPdf.cs` — `DocToPdfBytesRaw` (render-only visual PDF).
+- `Fuchs/js/intranet/modules/fis.inv_shared.js` — `$inv.eAddress` structured dialog.
+- `Fuchs_Database` — `fds__invoices.SendToAddressJson`, `fds__getCompanyAddressJson`,
+  `fds__prepInvoice.invoiceaddressData`, `fds__createInvoice`/`setInvoice`/`getInvoice`.
+- `eRechnungLib/**` — CII/UBL serialization, EN 16931 validation, `FacturXPdfBuilder` (PDF/A-3).
+
+## Related decisions
+- [`0005-pdf-generation-and-erechnung.md`](../Decisions/0005-pdf-generation-and-erechnung.md)
+- [`0012-erechnung-single-pdfa-engine-pipeline.md`](../Decisions/0012-erechnung-single-pdfa-engine-pipeline.md)

Fuchs/Docs/Concepts/live-draft-editing.md

@@ -0,0 +1,153 @@
+---
+status: Active
+lastUpdated: 2026-07-10
+applyTo:
+  - "Fuchs/Services/InvoiceDraft*"
+  - "Fuchs/Services/IInvoiceDraft*"
+  - "Fuchs/Services/ReminderDraft*"
+  - "Fuchs/Services/IReminderDraft*"
+  - "Fuchs/code/InvoiceDraftSession.cs"
+  - "Fuchs/code/InvoiceDraftCalculator.cs"
+  - "Fuchs/code/ReminderDraftSession.cs"
+  - "Fuchs/code/ReminderDraftCalculator.cs"
+  - "Fuchs/Notifications/DraftPreviewHub.cs"
+  - "Fuchs/Notifications/*DraftNotifier*"
+  - "Fuchs/Controllers/IntranetController.InvoiceDraft.cs"
+  - "Fuchs/Controllers/IntranetController.ReminderDraft.cs"
+  - "Fuchs/js/intranet/**"
+relatedDecisions:
+  - "0006-backend-authoritative-draft-editing.md"
+  - "0007-targeted-draft-signalr-groups.md"
+---
+
+# Live draft editing (backend-authoritative invoice previews)
+
+## Summary
+While a back-office user edits an invoice draft, the authoritative state is held in
+server memory, not in the browser. The browser posts single edits, the server mutates
+the cached record, recomputes totals/VAT and re-validates, then pushes a "state changed"
+signal so the browser re-fetches and re-renders. This makes the backend the single source
+of truth (server-computed sums, consistency checks, in-place PDF preview, change history,
+explicit discard), reversing the earlier stateless editor. Invoices were the pilot;
+reminders now mirror the same design (see "Reminders" below).
+
+## How it works
+
+```
+Open:     Browser --POST inv/dopen {id | payload}--> server builds InvoiceDraftSession, caches it
+          Browser --SignalR JoinDraft(token)--> joins the draft's group; spinner while loading
+          Browser --POST inv/dstate {token}--> renders admin/new/req + server sums + validation
+
+Edit:     Browser --POST inv/dpatch {token, delta}--> mutate + recompute + validate + version++
+          Server  --SignalR draftReady{token,version}--> Browser re-fetches inv/dstate, re-renders
+
+Preview:  Browser --POST inv/dpreview {token}--> PDF rendered straight from the cache (no upload)
+Save:     Browser --POST inv/dsave {token}--> flush cache->DB (RegisterInvoiceAsync) + EventService toast
+History:  Browser --POST inv/dhistory {token}--> change list -> "Änderungshistorie" dialog
+Discard:  Browser --POST inv/ddiscard {token}--> reload session from DB draft -> draftReady
+Close:    Browser --POST inv/dclose {token}--> session removed (+ LeaveDraft)
+
+Expiry:   Server (timer) --SignalR draftExpiring{token,secondsLeft}--> warn "bitte zwischenspeichern"
+          Server (evict) --SignalR draftClosed{token,reason}--> close the editor with a reason
+```
+
+- **Session** (`InvoiceDraftSession`) is a pure data holder: the editable payload as the
+  exact editor JSON (`admin` / `new` / `req` blocks with `items`), plus server-computed
+  `Sums`, `ValidationMessages`, `History`, `Version`, `Token`, `InvId`, `LastAccessUtc`.
+- **Calculation** (`InvoiceDraftCalculator`, static/pure) ports the former client math:
+  `RecomputeLineValues` (net/VAT/service-net/service-VAT per line from raw quantity ×
+  price × VAT rate, the `quantChange`/`setVat` port), `RecomputeTotals`
+  (the `invSumUpdate`/`csms` aggregation + §13b reverse-charge), `RecomputePositions`
+  (numbers every line except heading/free-text lines continuously across the whole invoice —
+  mirroring the editor's `invSumUpdate`, so the editor and the PDF show identical `Pos.` numbers,
+  including after a reorder),
+  and `Validate` (email/address/items/VAT-rate/negative-total checks). Being pure, it is
+  exhaustively unit-tested. **The online editor performs no arithmetic of any kind** — not
+  header, footer, sums, totals, taxes, nor a single line's own net/VAT value: `$inv.quantChange`
+  and `$inv.setVat` only post the raw field the user changed (qty/price/vat rate), and
+  `$inv.invSumUpdate` only reassembles the row-contract array needed to post `req` — it computes
+  no totals, no VAT breakdown, and no service-refund note figures. All of those are rendered
+  exclusively from `dstate.sums` via `$inv.d.footer`.
+- **Sanitisation & reorder.** Scalar text deltas (`title`/`email`/`address`/`provisionperiod`/
+  `provisionlocation`) and the section heading (`block.replace`) are stripped of the editor's
+  TinyMCE HTML (`<p>…</p>`, `<br>`) to plain text in `ApplyDelta` (`HtmlToPlain`) — the backend
+  is the single source of truth, so no HTML reaches the DB, the PDF or a reloaded draft. Section
+  drags post a `block.order` delta (`["id",…]`) that reorders `Req`; positions are then
+  renumbered and pushed back via the view state (`applyState`/`applyPositions`). The change
+  history records the **changed field** (e.g. the new heading text), never the whole block JSON.
+  The PDF (`FuchsPdf`) renders a heading row per block (`FdsInvoiceData.InvoiceBlocks`) and shows
+  every position's price (set members are priced like standalone lines; only `setonly` collapses
+  them), so the PDF preview mirrors the online editor.
+- **Orchestration** (`InvoiceDraftEditService`, scoped) opens sessions (from a fresh
+  payload or by reloading a DB draft via `fds__getInvoice`, reshaped like
+  `BuildInvoiceRequestList`), applies deltas (`ApplyDelta`), builds the view-state DTO,
+  flushes to the DB by reusing `IInvoiceService.RegisterInvoiceAsync` (no new persistence
+  path), renders previews from a synthesised registration, and discards by reloading.
+- **Cache** (`InvoiceDraftCache`, singleton) stores sessions by token with an idle sliding
+  TTL; `InvoiceDraftExpiryService` (a `BackgroundService`) warns before, and evicts after,
+  the TTL. TTL/warn-lead are configurable under `Fuchs:DraftEditing`.
+- **Signals** (`DraftPreviewHub` at `/draftpreview` + `IDraftNotifier`) are targeted at the
+  editing browser via a group named after the session token: `draftReady`, `draftExpiring`,
+  `draftClosed`. Business success/failure still flows through `IEventService`/`NotificationHub`.
+- **Frontend** (`$fis.draft` in `fis_main.js`, editor in `fis.inv_shared.js`) opens/joins,
+  posts one delta per change, shows a loading state whenever awaiting a signal, and offers
+  "Änderungen verwerfen" and "Änderungshistorie" menu actions. It computes nothing — no
+  header, footer, sums, totals, taxes, or per-line values.
+
+## Key files
+- `Fuchs/code/InvoiceDraftSession.cs` — session + `ChangeHistoryEntry` + `InvoiceDraftSums`.
+- `Fuchs/code/InvoiceDraftCalculator.cs` — pure recompute + validate.
+- `Fuchs/Services/InvoiceDraftCache.cs` / `IInvoiceDraftCache.cs` — in-memory store + TTL.
+- `Fuchs/Services/InvoiceDraftEditService.cs` / `IInvoiceDraftService.cs` — orchestration + delta contract.
+- `Fuchs/Services/InvoiceDraftExpiryService.cs` — idle warn/evict monitor.
+- `Fuchs/Notifications/DraftPreviewHub.cs`, `DraftNotifier.cs`, `IDraftNotifier.cs` — targeted signals.
+- `Fuchs/Controllers/IntranetController.InvoiceDraft.cs` — `inv/d*` endpoints.
+- `Fuchs/js/intranet/fis_main.js`, `Fuchs/js/intranet/modules/fis.inv_shared.js` — client.
+
+## Reminders (Zahlungserinnerung)
+
+Reminders mirror the same backend-authoritative model with a reminder-shaped session. A
+reminder chases a single invoiced amount, so the machinery is simpler than an invoice's:
+there are no line-item blocks, VAT grouping or reordering — just recipient fields and the
+amount pair.
+
+- **Endpoints** are `rem/d*` (`dopen`/`dstate`/`dpatch`/`dpreview`/`dsave`/`dhistory`/`dclose`),
+  dispatched from `Do_Process_Reminder`. Finalise + email still runs through the existing
+  `rem/conf` (`HandleReminderConf`), exactly as invoices finalise through `req/sconf`.
+- **Session** (`ReminderDraftSession`) holds the editor's `new` (subject / invoiceaddress /
+  invoiceemail / text / amount / amount_payed / CustomValues) and `rem` (invid / type /
+  invoiceid / invoicedate) blocks, plus server-computed `Sums` (`AmountTotal`, `AmountPayed`,
+  `AmountOpen`). It reuses the shared `ChangeHistoryEntry`; validation uses
+  `ReminderDraftValidationMessage`.
+- **Calculation** (`ReminderDraftCalculator`, static/pure): `AmountOpen = AmountTotal − AmountPayed`,
+  plus email/address/subject/open-amount plausibility checks. Exhaustively unit-tested.
+- **Deltas** (`ReminderDraftDelta`): scalar `email`/`address`/`subject`/`text` (HTML-sanitised via
+  the shared `InvoiceDraftEditService.HtmlToPlain`), the numeric `amount`/`amount_payed`
+  (normalised to an invariant decimal string), and `contact` (→ `CustomValues`).
+- **Orchestration** (`ReminderDraftEditService`, scoped) flushes to the DB by reusing
+  `IReminderService.RegisterReminderAsync`, and renders previews from a synthesised
+  `ReminderRegistration` (including the single-invoice `invoices` row the reminder PDF table
+  renders) so a preview needs no DB round-trip. **Note:** `RegisterReminderAsync` is create-only
+  (there is no `fds__setReminder` update proc), so a re-saved reminder draft does not update the
+  prior DB row — the primary flow (preview → confirm) flushes once immediately before finalising.
+- **Cache/expiry** (`ReminderDraftCache` singleton + `ReminderDraftExpiryService`) mirror the
+  invoice ones and share the same `Fuchs:DraftEditing` TTL config.
+- **Signals** reuse the shared `DraftPreviewHub` + `IDraftNotifier` unchanged — the token-keyed
+  groups serve invoice and reminder drafts alike.
+- **Frontend** (`$inv.rd` in `fis.inv_shared.js`) opens/joins on `rem/dopen`, posts one delta per
+  inline edit and per item-row amount change, renders the open-amount footer + validation from the
+  server state, and previews/finalises through `rem/dpreview` → `rem/dsave` → `rem/conf`. It shares
+  the invoice editor DOM; `$inv.d` and `$inv.rd` each key off their own token, so the shared inline
+  editor safely no-ops for whichever mode is inactive.
+
+### Reminder key files
+- `Fuchs/code/ReminderDraftSession.cs` — session + `ReminderDraftSums` + `ReminderDraftValidationMessage`.
+- `Fuchs/code/ReminderDraftCalculator.cs` — pure open-amount recompute + validate.
+- `Fuchs/Services/ReminderDraftCache.cs` / `IReminderDraftCache.cs` — in-memory store + TTL.
+- `Fuchs/Services/ReminderDraftEditService.cs` / `IReminderDraftService.cs` — orchestration + delta contract.
+- `Fuchs/Services/ReminderDraftExpiryService.cs` — idle warn/evict monitor.
+- `Fuchs/Controllers/IntranetController.ReminderDraft.cs` — `rem/d*` endpoints.
+
+## Related decisions
+- [0006 — Backend-authoritative draft editing](../Decisions/0006-backend-authoritative-draft-editing.md)
+- [0007 — Targeted draft SignalR groups](../Decisions/0007-targeted-draft-signalr-groups.md)

Fuchs/Docs/Decisions/0001-domain-events-and-notification-triggers.md

@@ -0,0 +1,67 @@
+---
+status: Accepted
+date: 2026-07-03
+applyTo:
+  - "Fuchs/Notifications/**"
+  - "Fuchs/Services/**"
+  - "Fuchs/Controllers/**"
+supersededBy: ""
+---
+
+# 0001 — Domain events (success and failure) trigger user-understandable notifications
+
+## Context
+Business operations (invoice creation, sending, marking sent, reminders,
+banking import) happen server-side, often outside a synchronous request the
+user is watching (background jobs, long-running sends). Users had no
+reliable way to learn that an operation they cared about — or one that
+failed — actually happened, short of refreshing lists or checking logs.
+
+## Decision
+Every meaningful business outcome, success **and** failure, is modeled as a
+`DomainEvent` (`Fuchs/Notifications/DomainEvent.cs`) with:
+- a `DomainEventType` enum value identifying what happened,
+- the acting `UserAccountId`,
+- a `Title`, and
+- a `Context` dictionary of the data needed to render a human-readable
+  message (invoice number, email address, file name, row counts, etc.).
+
+Services call the corresponding method on `IEventService`
+(`Fuchs/Notifications/IEventService.cs`, implemented by `EventService`)
+at the point the outcome is known — e.g.
+`InvoiceSentToCustomerAsync(invoice, email, userAccountId)` or
+`InvoiceIssueAsync(message, userAccountId, invoiceId)` on failure.
+`EventService.PublishAsync` renders the event into a `GuiNotification` with a
+German, end-user-readable `Message` (e.g. *"Rechnung R2026-0001 wurde an den
+Kunden mit der E-Mail test@test.de versandt."*) and pushes it — see
+[0002](0002-gui-notification-delivery-signalr.md) for delivery.
+
+Every new business operation with a user-visible outcome (created, sent,
+failed, imported, etc.) must add a `DomainEventType` value and a matching
+`IEventService` method, and call it from the service at the point of success
+**and** the point of failure.
+
+## Consequences
+- `IEventService` is injected into services that perform user-facing
+  operations (`InvoiceService`, `ReminderService`, `BankingService` callers)
+  — never bypass it by writing directly to `NotificationHub`.
+- Failure paths must call the `*IssueAsync`/`*Failed` event too, not just
+  succeed-path events — silent failures are the problem this exists to
+  prevent.
+- Messages are built server-side in `EventService.BuildNotification`, in
+  German, using only `Context` values — keep `Context` populated with
+  everything the message needs (don't rely on the client to look anything
+  up).
+- Adding a new event type means updating the enum, the `IEventService`
+  interface + `EventService` implementation (trigger method + message
+  branch + `IsFailure` if it's a failure type), and the calling service —
+  in the same change.
+
+## Alternatives considered
+- **Polling a status endpoint from the client**: rejected — adds latency,
+  extra load, and doesn't generalize to background/multi-tab flows as
+  cleanly as a push model.
+- **Raw exception messages surfaced to the GUI**: rejected — not
+  user-understandable and leaks internal details; `Context` + a rendered
+  German message keeps the boundary between internal errors and
+  user-facing text explicit.

Fuchs/Docs/Decisions/0002-gui-notification-delivery-signalr.md

@@ -0,0 +1,60 @@
+---
+status: Accepted
+date: 2026-07-03
+applyTo:
+  - "Fuchs/Notifications/**"
+  - "Fuchs/js/intranet/**"
+  - "Fuchs/wwwroot/web/**"
+  - "Fuchs/Program.cs"
+supersededBy: ""
+---
+
+# 0002 — Backend notifications reach the GUI via a SignalR push to every logged-in session
+
+## Context
+Domain events (see [0001](0001-domain-events-and-notification-triggers.md))
+need to reach whichever browser session(s) a user has open, in near
+real time, without the client polling.
+
+## Decision
+- `NotificationHub` (`Fuchs/Notifications/NotificationHub.cs`) is an
+  `[Authorize]` SignalR `Hub` mapped at `/notifications` in `Program.cs`
+  (`app.MapHub<NotificationHub>("/notifications")`).
+- `EventService.PublishAsync` sends every `GuiNotification` to
+  `_hub.Clients.All.SendAsync("notification", notification, ...)`. Delivery
+  is currently broadcast to all connected (authenticated) clients, not
+  targeted per-user — any logged-in session receives every notification.
+- Publish failures are caught and logged (`_logger.LogWarning`) rather than
+  thrown — a notification-delivery failure must never fail the underlying
+  business operation that triggered it.
+- On the client, `$fis.notifications` (`Fuchs/js/intranet/fis_main.js`)
+  opens the SignalR connection once a logged-in `useraccount_id` is known,
+  listens for the `"notification"` event, and calls `push(notification)`
+  to render a dismissible toast into `#notification_frame`. The toast is
+  styled by `notification.severity` (`"error"` vs `"info"`), giving failures
+  a distinct highlighted appearance from successes.
+- `GuiNotification.Severity` is derived by `EventService.IsFailure` from the
+  `DomainEventType` — failure event types render as `"error"`, everything
+  else as `"info"`.
+
+## Consequences
+- Any new `DomainEventType` that represents a failure must be added to
+  `EventService.IsFailure` or it will render as a plain info toast instead
+  of being visually flagged.
+- Because delivery is broadcast (not user-scoped), notifications are not a
+  substitute for private/sensitive data — `Context`/`Message` content must
+  stay appropriate for any logged-in user to see. If per-user targeting
+  becomes necessary, that is a new decision (SignalR groups keyed by user
+  ID), not a silent change to this one.
+- The hub requires authentication; unauthenticated sessions never connect
+  and never receive notifications.
+- Frontend rendering logic lives in `fis_main.js`/`fis.js` — keep the built
+  `wwwroot/web/fis.js`/`fis.min.js` in sync via the gulp build (see
+  `CLAUDE.md` Build & Test) whenever the notification client code changes.
+
+## Alternatives considered
+- **Per-user SignalR groups**: more correct long-term but adds group
+  join/leave lifecycle management; deferred until a concrete need for
+  private notifications arises.
+- **Server-Sent Events / long polling**: rejected — SignalR was already the
+  chosen real-time transport and needs no extra infrastructure.

Fuchs/Docs/Decisions/0003-interrupting-exceptions-notify-the-user.md

@@ -0,0 +1,72 @@
+---
+status: Accepted
+date: 2026-07-08
+applyTo:
+  - "Fuchs/Controllers/**"
+  - "Fuchs/Services/**"
+  - "Fuchs/Notifications/**"
+supersededBy: ""
+---
+
+# 0003 — Any exception that interrupts a user action notifies the user (not just the log)
+
+## Context
+[0001](0001-domain-events-and-notification-triggers.md) requires the *modeled*
+failure paths (invoice/reminder/banking create, send, import) to publish a
+`*IssueAsync`/`*Failed` event. But an action can also fail through an
+**unexpected/unmodeled** exception — a bug, a transient dependency error, an
+edge case nobody wrote a specific failure event for. Those were only landing in
+the log (`_logger.LogError` + an HTTP 500), so the user saw the action stop with
+no explanation and no notification. The user asked that *whenever* an exception
+interrupts a process they initiated, they be told via the notification system.
+
+## Decision
+Every exception that **interrupts a user-initiated action** must surface to the
+user through `IEventService`, in addition to being logged. Concretely:
+
+- **Catch-all safety net at the dispatcher.** `IntranetController.Do`'s
+  top-level `catch` publishes a generic `UserIssueAsync("Aktion fehlgeschlagen",
+  …)` for any `Do_Process_*` action that throws without having already published
+  its own (more specific) issue event. It is guarded by
+  `UserIdent.IsAuthenticated` — pre-auth flows (login/logout, anonymous GETs)
+  have no session to notify and the HTTP status already conveys the failure.
+- **Handlers with their own `catch` must notify locally.** A handler that
+  swallows its exception (returns a 500/error result instead of rethrowing)
+  never reaches the `Do` net, so it must call the matching issue event itself —
+  e.g. `HandleInvoiceGet` calls `InvoiceIssueAsync` before returning 500. Prefer
+  the domain-specific method (`InvoiceIssueAsync`/`ReminderIssueAsync`/
+  `BankingImportIssueAsync`); fall back to `UserIssueAsync` when none fits.
+- **Message stays user-readable and broadcast-safe.** Per
+  [0002](0002-gui-notification-delivery-signalr.md) notifications are broadcast
+  to every logged-in session, so the German `Message`/`Context` must never carry
+  the raw exception text or anything sensitive — diagnostics go to the log; the
+  user gets a plain "could not be completed" message.
+
+This deliberately **excludes** operations that do not interrupt a discrete user
+action: background/best-effort work (blob archiving, startup self-tests,
+per-entry parse skips) stays log-only, and auto-refreshing read views (dashboard
+widgets, report reloads) return their error status without a toast, because
+notifying on every poll cycle would spam the user rather than inform them.
+
+## Consequences
+- New `catch` blocks on a request-handling path must be classified: does the
+  exception interrupt a user action? If yes → publish an issue event (specific
+  if one exists, else `UserIssueAsync`). If it is background/best-effort or an
+  auto-poll read → log only, and say so in a comment.
+- The `Do` net is a backstop, not a replacement for specific events: modeled
+  failures should still publish their contextful `*IssueAsync` at the point of
+  failure so the message names the invoice/reminder/file involved.
+- Because the net only fires on *unhandled* exceptions (handled flows return
+  rather than rethrow), it does not double-notify the flows that already report
+  their own failures.
+
+## Alternatives considered
+- **Rely solely on 0001's per-flow issue events**: rejected — it leaves every
+  unmodeled/unexpected exception silent, which is exactly the gap the user
+  reported.
+- **Notify on every failing read/poll too (widgets, reports)**: rejected —
+  auto-refresh would turn a transient backend hiccup into a stream of toasts;
+  those paths surface failure via HTTP status instead.
+- **Surface the raw exception message to the GUI**: rejected for the same
+  reason as 0001 — not user-understandable, leaks internals, and (per 0002) is
+  visible to every logged-in session.

Fuchs/Docs/Decisions/0003-structured-diagnostic-logging.md

@@ -0,0 +1,56 @@
+---
+status: Accepted
+date: 2026-07-03
+applyTo:
+  - "Fuchs/Logging/**"
+  - "Fuchs/Program.cs"
+supersededBy: ""
+---
+
+# 0003 — The solution is equipped with structured diagnostic logging
+
+## Context
+Diagnosing issues in a deployed intranet instance requires a durable,
+inspectable log of what the application did, independent of whether an
+OpenTelemetry collector is attached (see
+[0004](0004-opentelemetry-observability.md)) — logging must work
+out-of-the-box on every environment with zero external dependencies.
+
+## Decision
+- `Fuchs/Logging/FuchsLoggerProvider.cs` implements a custom
+  `ILoggerProvider`/`ILogger` registered via `builder.Logging.AddFuchsLogging()`
+  in `Program.cs`, with `SetMinimumLevel(LogLevel.Debug)`.
+- Every log line always goes to `Debug.WriteLine` **and** to a rolling text
+  file under `<content root>/logs/` — `AppLog.txt` for
+  `Debug`/`Information`/`Warning`, `ErrorLog.txt` for `Error`/`Critical` —
+  so a failure investigation never depends on a debugger being attached.
+- Log lines are structured with timestamp, level tag, category, message, and
+  (when present) the exception message + stack trace on continuation lines.
+- Database logging (`fuchs__admin_logdebug`) is **prepared but disabled** by
+  default (`FuchsLoggerProvider.DatabaseLoggingEnabled = false`) — flip it
+  on only where DB-durable diagnostics are specifically needed, since it
+  adds a DB round-trip per log call.
+- All logger calls elsewhere in the codebase use `ILogger<T>` injected via
+  DI with **structured** placeholders (`_logger.LogInformation("Sent {InvoiceNumber} to {Email}", ...)`),
+  never interpolated strings — this is enforced project-wide (see Coding
+  Standards / Observability in `CLAUDE.md`).
+- File writes are best-effort: `AppendToFile` swallows its own exceptions —
+  a logging failure must never crash or interrupt the operation being
+  logged.
+
+## Consequences
+- New code must inject `ILogger<T>` and log entry/result/timing/errors for
+  meaningful operations (see [0004](0004-opentelemetry-observability.md) for
+  the matching tracing/metrics requirement) rather than adding ad-hoc
+  `Console.WriteLine`/`Debug.Print` calls.
+- Because logs always write to `logs/AppLog.txt` and `ErrorLog.txt`
+  regardless of telemetry configuration, these files are the first place to
+  check when OTLP export isn't configured for an environment.
+- Enabling `DatabaseLoggingEnabled` is a deliberate, explicit choice per
+  environment, not a default — it has a per-call DB cost.
+
+## Alternatives considered
+- **Third-party logging framework (Serilog/NLog)**: rejected for now to
+  avoid an extra dependency for a need the in-box `ILogger` abstraction plus
+  a small custom provider already satisfies; revisit if requirements (e.g.
+  structured JSON sinks, log shipping) outgrow this.

Fuchs/Docs/Decisions/0004-opentelemetry-observability.md

@@ -0,0 +1,65 @@
+---
+status: Accepted
+date: 2026-07-03
+applyTo:
+  - "Fuchs/Observability/**"
+  - "Fuchs/Program.cs"
+  - "Fuchs/Services/**"
+supersededBy: ""
+---
+
+# 0004 — OpenTelemetry is wired in extensively, without compromising performance
+
+## Context
+Beyond text logs (see [0003](0003-structured-diagnostic-logging.md)), the
+solution needs distributed tracing and metrics to understand performance and
+behavior in production (PDF render durations, email send outcomes, MFR call
+volume, banking import throughput) without depending on a debugger or manual
+log-grepping — while never letting the absence of a collector break or slow
+down the app.
+
+## Decision
+- All instrumentation is centralized in `Fuchs/Observability/FuchsTelemetry.cs`:
+  one `ActivitySource` (`Fuchs.Intranet`) for tracing and one `Meter` for
+  metrics, exposing named `Counter<long>`/`Histogram<double>` instruments
+  (invoices/reminders/reports rendered, emails/SMS sent/failed, MT940 rows
+  parsed, banking entries skipped/truncated, MFR calls, blob upload
+  success/failure, PDF/report/email durations) plus a `StartActivity` helper.
+- Wired in `Program.cs` behind `Fuchs:Telemetry:Enabled` (default `true`):
+  `AddOpenTelemetry()` with `AddAspNetCoreInstrumentation`,
+  `AddHttpClientInstrumentation`, `AddSqlClientInstrumentation` for tracing,
+  and `AddAspNetCoreInstrumentation`, `AddHttpClientInstrumentation`,
+  `AddRuntimeInstrumentation` for metrics.
+- **Collection is always on; export is opt-in.** The OTLP exporter is only
+  added when `Fuchs:Telemetry:OtlpEndpoint` is configured — with no
+  collector present, spans/metrics are simply collected in-process and
+  discarded, so a missing collector can never cause startup failures,
+  exceptions, or blocking calls. Setting `Fuchs:Telemetry:Enabled=false`
+  disables instrumentation entirely.
+- Per the project-wide Observability standard: every meaningful operation
+  starts an activity via `FuchsTelemetry.StartActivity(...)`, records the
+  matching counter/histogram, and logs entry/result/timing/errors via
+  injected `ILogger<T>` with structured placeholders — this is enforced for
+  new service/handler code, not just the initial wiring.
+
+## Consequences
+- New business operations worth observing must add a named instrument to
+  `FuchsTelemetry.cs` rather than creating ad-hoc `ActivitySource`/`Meter`
+  instances elsewhere — one source, one meter, keeps exporters and
+  dashboards simple.
+- Because export is opt-in, local/dev environments get full in-process
+  instrumentation with zero setup; wiring an OTLP collector is purely an
+  ops-side configuration change (`Fuchs:Telemetry:OtlpEndpoint`), not a
+  code change.
+- Instrumentation must stay cheap on the hot path — use the existing
+  counters/histograms rather than allocating new tags/dictionaries per call
+  where avoidable, and never make a business operation depend on the
+  exporter succeeding.
+
+## Alternatives considered
+- **Always-on OTLP exporter requiring a collector**: rejected — would make
+  local dev and any environment without a collector fail hard or add
+  latency/timeouts trying to reach one.
+- **Per-service ActivitySource/Meter instances**: rejected in favor of one
+  centralized `FuchsTelemetry` — avoids scattered instrument names and
+  duplicate registration boilerplate in `Program.cs`.

Fuchs/Docs/Decisions/0005-pdf-generation-and-erechnung.md

@@ -0,0 +1,84 @@
+---
+status: Accepted
+date: 2026-07-05
+applyTo:
+  - "Fuchs/code/FuchsPdf.cs"
+  - "Fuchs/Services/FuchsPdfService.cs"
+  - "Fuchs/Services/InvoiceService.cs"
+  - "Fuchs/Services/ReminderService.cs"
+  - "eRechnungLib/**"
+supersededBy: ""
+---
+
+# 0005 — PDF generation, rendering, and eRechnung output
+
+## Context
+Fuchs produces letters, invoices, and reminders as PDFs. The layout is a faithful
+port of the legacy VB module `fuchs_fds_pdf.vb` (letterhead, DIN address window,
+admin block, four-block footer with page numbers, invoice item table, GiroCode).
+The port had silently drifted — wrong letterhead image filenames (`image1.png`
+instead of the shipped `image1.jpeg`, which `AddHeaderImage` skips via
+`File.Exists`), a too-small bottom margin, and a reworked footer/admin block — so
+generated PDFs (e.g. the `sprep` invoice preview) rendered broken.
+
+Separately, German B2B/B2G invoicing now requires **eRechnung** (structured
+electronic invoices). The company direction is that **all invoices are emitted as
+eRechnung**, not just human-readable PDFs.
+
+Rendering also depends on **Spire.PDF** (commercial, licensed) for PDF/A
+conversion and rasterising PDFs to preview images.
+
+## Decision
+- **PDF layout stays a 1:1 port of the legacy `fuchs_fds_pdf.vb`.** `FuchsPdf`
+  (MigraDoc/PdfSharp) is the single source of the visual layout. When changing
+  the letter/invoice/reminder layout, compare against the legacy module and keep
+  the letterhead assets (`Fuchs/Data/image1-3.jpeg`, `image4.png`, `overlay.png`),
+  margins, sender line, label-over-value admin block, absolutely-positioned
+  four-block footer, and `Seite X von Y` page numbers aligned with it. Reference
+  the shipped asset filenames exactly — `AddHeaderImage` no-ops on a missing file,
+  so a wrong extension silently drops a logo.
+- **Rendering pipeline:** `FuchsPdf.DocToPdfBytes` renders MigraDoc → PDF and
+  post-processes to PDF/A; `DocToImageCollection` / `BytesToImageCollection`
+  rasterise via Spire for the on-screen invoice preview (`sprep`/`sedit`). The
+  OCORE `OCOREFontResolver` must be installed before any PdfSharp rendering.
+- **Spire license comes from a managed secret.** `FuchsPdfService` reads the
+  license from configuration key `SpirePdf_License` (Key Vault secret
+  `fuchs--SpirePdf-License`, registered in `ManagedSecretKeys`) and passes it to
+  `FuchsPdf.SetLicense(key)`. An embedded fallback key keeps local/dev rendering
+  working without Key Vault.
+- **eRechnung via `eRechnungLib`.** The `eRechnungLib` submodule is the single
+  library for structured invoices. Invoices are to be produced as eRechnung:
+  build an `eRechnungLib.Model.Invoice` from the Fuchs invoice data, then
+  `EInvoice.CreateInvoice(model).ToZugferd(ZugferdProfile.EN16931, visualPdfBytes)`
+  to embed the CII XML into the FuchsPdf-rendered visual PDF (ZUGFeRD/Factur-X
+  hybrid PDF/A-3), or `ToXRechnung(...)` for pure UBL/CII XML. The visual PDF is
+  the FuchsPdf output — the two layers stay consistent (same amounts/parties).
+  Default `ConversionOptions` runs model + XSD validation; use `StrictValidation`
+  when a malformed invoice must withhold output rather than ship with findings.
+
+## Consequences
+- Layout edits must be validated against the legacy reference and the shipped
+  `Data/` assets; do not invent new positions/sizes. The pipeline test
+  `Fuchs.Tests/PdfPipelineTests.cs` exercises the full chain (PdfSharp visual PDF
+  → Spire preview images → eRechnung hybrid/XML) and must stay green.
+- Do **not** upgrade Spire.PDF beyond 8.10.5 (see project libraries rule). The
+  license must never be hard-coded in new code paths — read it from
+  `SpirePdf_License`.
+- Wiring the app's invoice flow to emit eRechnung is the follow-up: map
+  `FdsInvoiceData`/`InvoiceRegistration` → `eRechnungLib.Model.Invoice`
+  (parties, lines, VAT breakdown, payment/IBAN, buyer reference, seller
+  electronic address) and persist/deliver the ZUGFeRD PDF and/or XRechnung XML.
+- eRechnungLib depends only on open-source libraries (PDFsharp/MigraDoc; optional
+  SaxonCS-HE for Schematron) — no new commercial dependency for the structured
+  output itself.
+
+## Alternatives considered
+- **Hand-rolling ZUGFeRD/XRechnung XML** in Fuchs: rejected — EN 16931 + CIUS
+  validation, multiple profiles/syntaxes, and PDF/A-3 embedding are error-prone;
+  a dedicated, validated library is safer.
+- **Rewriting the PDF layout from scratch** rather than porting the legacy module:
+  rejected — the letterhead is a fixed corporate design; the legacy VB is the
+  authoritative spec, so faithful porting avoids visual regressions.
+- **Bundling a Spire license file / hard-coding the key**: rejected in favor of
+  the managed-secret path so the production key is centrally rotated and never
+  committed, with the embedded key only as a dev fallback.

Fuchs/Docs/Decisions/0006-backend-authoritative-draft-editing.md

@@ -0,0 +1,90 @@
+---
+status: Accepted
+date: 2026-07-10
+applyTo:
+  - "Fuchs/Services/InvoiceDraft*"
+  - "Fuchs/Services/IInvoiceDraft*"
+  - "Fuchs/code/InvoiceDraftSession.cs"
+  - "Fuchs/code/InvoiceDraftCalculator.cs"
+  - "Fuchs/Notifications/DraftPreviewHub.cs"
+  - "Fuchs/Notifications/*DraftNotifier*"
+  - "Fuchs/Controllers/IntranetController.InvoiceDraft.cs"
+  - "Fuchs/js/intranet/**"
+supersededBy: ""
+---
+
+# 0006 — Invoice draft editing is backend-authoritative over an in-memory cache
+
+## Context
+The invoice editor was deliberately **stateless**: the browser held the working
+model, computed totals/VAT client-side (`invSumUpdate` in `fis.inv_shared.js`) and
+re-posted the whole `invc` JSON on every preview/save. `EVAL_live_invoice_editing.md`
+(2026) recommended keeping it that way and **against** a server-cached, SignalR-driven
+model, because the real-time/co-editing benefits were weak for a single back-office
+editor.
+
+The product owner has since decided the trade-off differently and prioritised a
+**single source of truth in the backend** with server-computed sums, server-side
+plausibility/consistency checks, in-place PDF preview without re-upload, an automatic
+change history, and an explicit discard. This decision records that reversal and the
+architecture chosen to implement it.
+
+## Decision
+While a user edits an invoice draft, the authoritative state lives **server-side** in
+an in-memory `InvoiceDraftSession` (`Fuchs/code/InvoiceDraftSession.cs`), held by the
+singleton `IInvoiceDraftCache` and orchestrated by the scoped `IInvoiceDraftService`
+(`InvoiceDraftEditService`). The browser is a pure view/input layer.
+
+- **Truth & calculation on the server.** `InvoiceDraftCalculator` is the pure,
+  unit-tested port of the former client-side math (`quantChange` + `setVat` +
+  `invSumUpdate`), including per-line net/VAT/service-value multiplication
+  (`RecomputeLineValues`), the §13b reverse-charge rule and VAT-per-rate grouping. The
+  browser performs **no arithmetic whatsoever** — not even a single line's
+  `net = qty × price` — it only renders the server's `req`/`sums`.
+- **Commands are ordinary POSTs; signals are SignalR.** The editor posts single edits
+  to `inv/dpatch` (and `dopen`/`dstate`/`dpreview`/`dsave`/`dhistory`/`ddiscard`/`dclose`).
+  The server mutates the session, recomputes, validates, bumps a version, and pings the
+  editing browser (`draftReady`) to re-fetch `inv/dstate`. See
+  [0007](0007-targeted-draft-signalr-groups.md) for the targeted-signal transport.
+- **Cache-only until Zwischenspeichern/Finalise.** Opening builds the session (from a
+  brand-new payload or by reloading a DB draft); edits touch only the cache. `dsave`
+  flushes the session to the DB by reusing the existing
+  `IInvoiceService.RegisterInvoiceAsync` — **no new persistence path** — and reports
+  success/failure through the existing `IEventService` (ADR 0001). Finalise continues
+  through `req/sconf`.
+- **Preview from cache.** `inv/dpreview` renders the draft PDF straight from the session
+  (synthesised registration), with no client upload.
+- **Automatic change history.** Every applied patch appends a `ChangeHistoryEntry`
+  (cache-only, never persisted); `inv/dhistory` exposes it for the "Änderungshistorie"
+  dialog.
+- **Idle lifecycle with user warning.** `InvoiceDraftExpiryService` warns the editing
+  browser before a session's idle TTL lapses (`draftExpiring`) and, on eviction, tells
+  it to close the editor with a reason (`draftClosed`). TTL and warning lead are under
+  `Fuchs:DraftEditing`.
+
+## Consequences
+- The server is now **stateful for in-progress drafts**. This is acceptable for a
+  single-instance deployment; **scale-out requires sticky sessions or a distributed
+  cache/SignalR backplane** — none exist today, so this is a documented limitation, not
+  a silent assumption.
+- New editor interactions must be modelled as a **delta** applied server-side (add a
+  case in `InvoiceDraftEditService.ApplyDelta` + calculator handling), never as a new
+  client-side calculation. Do not reintroduce client-side totals.
+- `FdsInvoiceData` stays a pure data holder; `InvoiceDraftSession` is likewise a data
+  holder, with all logic in the service/calculator (mirrors the existing service split).
+- Reminders (Mahnungen) are intended to follow the identical pattern as a second phase;
+  this decision covers invoices first (the pilot) and applies to the reminder mirror
+  when built.
+- `EVAL_live_invoice_editing.md` and `INVOICE_LIFECYCLE.md` §4/§10 (the "stateless
+  editor" invariant) are superseded by this decision for the draft-editing flow and have
+  been annotated accordingly.
+
+## Alternatives considered
+- **Keep the stateless editor** (the prior recommendation): rejected by the product
+  owner in favour of a backend single source of truth.
+- **Full bidirectional SignalR hub for commands too**: rejected — edits as POSTs reuse
+  the existing controller/auth pattern and avoid a command reconnect/replay protocol; the
+  hub carries only coordination signals.
+- **Write-through to the DB on every edit**: rejected — conflicts with the
+  "Zwischenspeichern = persist the cache" semantics and adds DB load; the cache is the
+  truth until an explicit save/finalise.

Fuchs/Docs/Decisions/0007-targeted-draft-signalr-groups.md

@@ -0,0 +1,59 @@
+---
+status: Accepted
+date: 2026-07-10
+applyTo:
+  - "Fuchs/Notifications/DraftPreviewHub.cs"
+  - "Fuchs/Notifications/IDraftNotifier.cs"
+  - "Fuchs/Notifications/DraftNotifier.cs"
+  - "Fuchs/Program.cs"
+  - "Fuchs/js/intranet/**"
+supersededBy: ""
+---
+
+# 0007 — Draft-editing signals are targeted via a dedicated hub with per-draft groups
+
+## Context
+Backend-authoritative draft editing (ADR 0006) needs to notify **exactly the one
+browser** editing a given draft that its cached state changed, is about to expire, or
+was closed. The existing `NotificationHub` (ADR 0002) deliberately **broadcasts** every
+business toast to all logged-in sessions and explicitly deferred per-user/targeted
+delivery as "a new decision". Draft coordination pings are high-frequency, per-editor,
+and must not spray to every session.
+
+## Decision
+Draft signals use a **dedicated** SignalR hub, `DraftPreviewHub`, mapped at
+`/draftpreview` (separate from `NotificationHub` at `/notifications`). Targeting is by
+**SignalR group named after the draft's session token**:
+
+- The client calls the hub methods `JoinDraft(token)` / `LeaveDraft(token)` to
+  subscribe/unsubscribe its connection to a draft's group. The hub carries **no
+  commands** — only group membership (edits are POSTs; see ADR 0006).
+- The server sends via `IDraftNotifier` (`DraftNotifier`) to `Clients.Group(token)`:
+  `draftReady{token,version}` (re-fetch), `draftExpiring{token,secondsLeft}` (idle
+  warning), `draftClosed{token,reason}` (session evicted/discarded → close the editor).
+- Like `EventService`, delivery failures are logged and swallowed — a missed
+  coordination ping must never fail the underlying operation; the client also re-syncs on
+  reconnect and on its next POST.
+
+Business success/failure messages for draft operations (e.g. "Zwischenstand
+gespeichert") continue to flow through `IEventService`/`NotificationHub`, **not** this
+hub — the two channels stay separate.
+
+## Consequences
+- The session **token doubles as the group name**; it is an opaque GUID and must not
+  encode sensitive data. Any browser that knows a token can join its group, so tokens
+  must be treated as capabilities and only handed to the authenticated editor that opened
+  the draft.
+- Adding a new draft signal means adding a method to `IDraftNotifier` + `DraftNotifier`
+  and a client handler in `$fis.draft` — not overloading the business notification path.
+- ADR 0002 is unchanged: `NotificationHub` stays broadcast-only for toasts. This hub is
+  the answer to its "if per-user targeting becomes necessary, that is a new decision".
+- Multi-instance scale-out needs a SignalR backplane for group delivery — same limitation
+  as ADR 0006.
+
+## Alternatives considered
+- **Reuse `NotificationHub` with groups**: rejected — it would entangle broadcast toasts
+  with targeted, high-frequency editing pings and force ADR 0002's broadcast contract to
+  change. A separate hub keeps the concerns and their decisions independent.
+- **Per-user groups (by account id)**: rejected — a user may open two drafts/tabs;
+  per-draft-token groups target the precise editor and naturally support that.

Fuchs/Docs/Decisions/0008-invoices-and-reminders-fully-backend-authoritative.md

@@ -0,0 +1,114 @@
+---
+status: Accepted
+date: 2026-07-15
+applyTo:
+  - "Fuchs/Services/InvoiceDraft*"
+  - "Fuchs/Services/IInvoiceDraft*"
+  - "Fuchs/Services/ReminderDraft*"
+  - "Fuchs/Services/IReminderDraft*"
+  - "Fuchs/code/InvoiceDraftSession.cs"
+  - "Fuchs/code/InvoiceDraftCalculator.cs"
+  - "Fuchs/code/InvoiceSetPricing.cs"
+  - "Fuchs/code/ReminderDraftSession.cs"
+  - "Fuchs/code/ReminderDraftCalculator.cs"
+  - "Fuchs/code/FuchsPdf.cs"
+  - "Fuchs/js/intranet/**"
+supersededBy: ""
+---
+
+# 0008 — Invoices and reminders (all kinds) are fully backend-authoritative; PDF and online editor must render identical content
+
+## Context
+ADR [0006](0006-backend-authoritative-draft-editing.md) established the backend-authoritative
+draft-editing model for invoices and noted reminders were "intended to follow the identical
+pattern as a second phase". Both are now implemented (`InvoiceDraftEditService` /
+`ReminderDraftEditService`). In practice, ambiguity kept resurfacing about *which* invoice/
+reminder kinds this covers and *which* kinds of change qualify as "must be computed server-side":
+e.g. whether a purely presentational client-side re-render (set-price display toggle, item
+reordering, position renumbering) was allowed to keep any client-side math, and whether this
+applies uniformly to every invoice type (regular `r`, partial/Abschlag `i`, final `f`, storno
+`c`) and every reminder stage, not just the pilot "regular invoice" flow. This decision closes
+that ambiguity explicitly.
+
+## Decision
+**Every invoice (all `InvoiceType` kinds: regular, partial/Abschlagsrechnung, final/
+Schlussrechnung, Storno/credit) and every reminder (all reminder stages/Mahnstufen) is
+backend-authoritative while being drafted or previewed.** This generalises and makes explicit
+what ADR 0006 already implied for the pilot flow:
+
+- **Any calculation** (net/VAT/gross totals, per-rate VAT grouping, service-refund figures,
+  §13b reverse-charge suppression, set-price sums, open-amount for reminders, position/line
+  numbering) is performed exclusively by the server (`InvoiceDraftCalculator`,
+  `ReminderDraftCalculator`, `InvoiceSetPricing`). The browser never sums, subtracts, or
+  otherwise derives a monetary or positional value — it only displays server-computed values.
+  This includes the single-line arithmetic that used to run in `quantChange`/`setVat`
+  (`net_val = qty × price`, `vat_val = net_val × rate`, service-net/-VAT splits): those
+  handlers now only post the raw, unmultiplied field the user typed (`qn`/`v`/`vat`) and the
+  server (`InvoiceDraftCalculator.RecomputeLineValues`) computes every derived line value.
+  Likewise the invoice footer (net/VAT-by-rate/gross), the per-block "isum" cell, and the
+  service-refund note figures are rendered exclusively from `dstate.sums` (`$inv.d.footer`);
+  `$inv.invSumUpdate` no longer accumulates any of these — it only reassembles the row
+  contract array needed to post `req` to the server and (on first load) seeds the session.
+- **Any setting** (§13b flag, set-pricing display mode, payment terms, contact, custom values,
+  …) is applied server-side via a named `InvoiceDraftDelta`/`ReminderDraftDelta` target and
+  reflected back through `dstate`. The client never mutates its local model as the source of
+  truth for a setting; it optimistically reflects the *request* but always re-renders from the
+  next `dstate`/`draftReady` refresh.
+- **Any text change** (recipient email/address, invoice title, provision location/period,
+  section headings, item name/description/notes) is sanitised and stored server-side
+  (`InvoiceDraftEditService.HtmlToPlain` et al.); the server's stored value is the one that
+  reaches the PDF and any reloaded draft.
+- **Any reordering** (drag-reorder of service-request blocks/sections, drag-reorder of item
+  rows within a block) is committed as a `block.order` (or equivalent) delta; the server
+  performs the actual reorder and renumbers positions (`InvoiceDraftCalculator.RecomputePositions`).
+  The client's drag interaction is input only — the rendered order after a refresh is the
+  server's order, not whatever the browser left in the DOM mid-drag.
+- **Irreversible one-way conversions** (e.g. "Auf Setpreis umstellen" — switching a set's
+  member items from individual prices to a single set price) are likewise backend-only
+  operations (`item.setprice` delta / `InvoiceDraftEditService.ApplyItemSetPrice`), never
+  computed or applied in the browser.
+- **The PDF must render 100% the same information and content as the online editor at any
+  given moment.** Both consume the identical authoritative session data:
+  - The online editor renders `dstate`'s `req`/`sums`/`setDisplay`/`notes` — all server-computed.
+  - The PDF preview (`inv/dpreview`, `rem/dpreview`) renders straight from the same cached
+	session via a synthesised registration (`InvoiceDraftEditService.RenderPreview` /
+	`ReminderDraftEditService`'s reminder equivalent) — **not** from a separate client upload
+	or a re-derived model.
+  - `FuchsPdf.BuildInvoiceNotes` (notice paragraphs) is called identically for both the
+	editor's `notes` array and the PDF body, so intro/closing texts can never drift between
+	the two renderings.
+  - Any new editor-visible fact (a new total, a new flag, a new note) must be added to the
+	shared session/service layer once, not duplicated as separate editor-only and PDF-only
+	logic.
+- This applies for the full lifecycle while a document is a draft (open → edit → preview →
+  Zwischenspeichern) up to finalise; a finalised, persisted invoice/reminder is immutable
+  and is rendered straight from its stored DB data (no draft session involved) — that path
+  already has no client-side math to begin with.
+
+## Consequences
+- New invoice/reminder editor features must be modelled as a server-side delta + calculator
+  change, exactly as ADR 0006 already requires; this decision removes any residual excuse to
+  special-case a "just this one is presentational, do it in JS" shortcut for reordering,
+  display-mode toggles, or one-way conversions.
+- Any PDF-only or editor-only special-casing found in review is a bug against this decision —
+  the shared session/service must be extended so both renderers read the same value/flag.
+- Reminder "Mahnstufen" and every invoice type share this obligation; there is no partial/
+  Abschlagsrechnung, Schlussrechnung, or Storno exemption while such a document is still a
+  draft going through the same `dopen`/`dpatch`/`dpreview`/`dsave` flow.
+- Test coverage for the cache/session layer (`InvoiceDraftEditService`, `ReminderDraftEditService`,
+  `InvoiceDraftCalculator`, `InvoiceSetPricing`) must exercise every mutating operation
+  (text edits, reordering, all three set-pricing display modes, the set-price conversion,
+  multi-rate VAT sums, full recompute) against mock datasets, since this is now the single
+  place all of these behaviours are guaranteed correct — see `Fuchs.Tests/InvoiceDraftServiceTests.cs`,
+  `Fuchs.Tests/ReminderDraftServiceTests.cs`, `Fuchs.Tests/InvoiceDraftCalculatorTests.cs`,
+  `Fuchs.Tests/InvoiceSetPricingTests.cs`.
+
+## Alternatives considered
+- **Scope this only to the invoice pilot flow** (leave reminders/other invoice kinds
+  ambiguous): rejected — the ambiguity itself was the problem being fixed; the underlying
+  session/service code already treats all kinds uniformly, so documenting anything narrower
+  would misrepresent the code.
+- **Allow "purely cosmetic" client-side math for reordering/display toggles**: rejected —
+  history showed exactly this exception is where drift crept in (e.g. the set-price toggle
+  originally computed sums in the browser before being moved server-side); no exception is
+  granted.

Fuchs/Docs/Decisions/0009-block-setprice-modes-are-irreversible-mutations.md

@@ -0,0 +1,122 @@
+---
+status: Accepted
+date: 2026-07-14
+applyTo:
+  - "Fuchs/code/InvoiceSetPricing.cs"
+  - "Fuchs/Services/InvoiceDraft*"
+  - "Fuchs/Services/IInvoiceDraft*"
+  - "Fuchs/code/InvoiceDraftSession.cs"
+  - "Fuchs/code/InvoiceDraftCalculator.cs"
+  - "Fuchs/code/FuchsPdf.cs"
+  - "Fuchs/js/intranet/**"
+  - "Fuchs/Docs/INVOICE_SET_PRICING.md"
+supersededBy: ""
+---
+
+# 0009 — The two menu set-price modes are per-service-request-block, irreversible cache mutations that insert a dedicated set row
+
+## Context
+ADRs [0006](0006-backend-authoritative-draft-editing.md) and
+[0008](0008-invoices-and-reminders-fully-backend-authoritative.md) made draft editing
+backend-authoritative. Under that model the set-price feature had **three** functions, of
+which the two menu-driven ones ("Set mit Preis" / "Nur Set mit Preis") were framed as
+whole-invoice **display modes** (`SetDisplayMode.SetPrice`/`SetOnly`): a non-mutating,
+render-time transform (`InvoiceSetPricing.Build`) over explicit `type == "set"` header items
+and their `SetItmId` members, persisted only as an `admin.setmode` flag. ADR 0008 calls them
+"display-mode toggles" and treats them as presentational.
+
+The product owner has redefined those two menu functions. They are **not** display toggles and
+they are **not** keyed on set-item membership:
+
+- Their grouping is the **service request** (`ServiceRequestId` = the editor's tbody block),
+  never `SetItmId`. Every block is treated as one set, whether or not it contains any
+  `type == "set"` item.
+- Applying a mode is an **irreversible data change** written hard into the cached draft
+  dataset — not a reversible view flag. There is no toggle back; the user adjusts the result
+  by hand afterwards.
+
+This decision records that redefinition. It **refines** ADR 0008's characterisation of these
+two operations (from "non-mutating display toggle" to "mutating, one-way conversion"); ADR
+0008's broader rule — every calculation server-side, and the PDF renders 100% the same content
+as the editor — remains fully in force and is not superseded.
+
+## Decision
+There are three distinct set-price operations, kept clearly separated:
+
+1. **Inline set-item switch — unchanged.** The row context button on a single `type == "set"`
+   item (`$inv.toSetPrice` → `item.setprice` delta → `InvoiceDraftEditService.ApplyItemSetPrice`).
+   It is `SetItmId`-based, sums the header's members onto the header, sets the members' prices to
+   `null` (empty cell, excluded from the sum — consistent with modes 2 & 3, not `0`), and is
+   one-way. This is the **only** set-price operation that reads `SetItmId`. The button is shown —
+   and the operation available — **only** for items that are `type == "set"` **and** carry a
+   `SetItmId` (and are still unconverted, i.e. own price `0`); an item missing either condition
+   never offers it.
+
+2. **"Set mit Preis" (menu) — per-block, irreversible mutation.** Applied server-side to the
+   cached `InvoiceDraftSession`, grouped by `ServiceRequestId`. For **every** service-request
+   block:
+   - Insert one dedicated, emphasised **set row** at the top of the block, carrying the block's
+     aggregated value (net + VAT + service-net/-VAT splits) as its price. This row is a real,
+     editable line item with its own id, so the user can manually change the set value afterwards
+     as an ordinary item edit.
+   - **Null out** the price of every existing item row in the block (set the price fields to
+     `null`, **not** `0`) so the row renders with an **empty** price/total cell. `null` and `0`
+     are semantically distinct here: `null` means "no price — render an empty cell and exclude
+     from the block sum", whereas `0` would legitimately print `0,00 €`. The rows themselves are
+     retained.
+
+3. **"Nur Set mit Preis" (menu) — per-block, irreversible mutation.** As above, grouped by
+   `ServiceRequestId`. For every block:
+   - Insert the same dedicated, emphasised set row carrying the block's aggregated value.
+   - **Remove** every existing item row in the block from the dataset entirely (the lines are
+     gone, not merely hidden).
+
+Properties common to the two menu modes (2 and 3):
+
+- **Mutation, not display.** The change is written into `InvoiceDraftSession.Req` (the "cache
+  dataset") as a mutating `InvoiceDraftDelta`, computed on the server (never in the browser).
+  There is no render-time `admin.setmode` grouping flag driving how lines are shown, and no
+  reversible toggle.
+- **Irreversible.** There is no patch to undo it. The only ways back are discarding the draft
+  (reloads the DB state) or hand-editing the resulting rows.
+- **`SetItmId` is irrelevant.** Membership is the block, full stop.
+- **Total unchanged.** The inserted set row's value equals the sum of the block's original items,
+  which are then excluded from the sum — either because their price is `null` (mode 2, `null`
+  counts as no contribution) or because they are gone (mode 3). So `InvoiceBalance`/
+  `InvoiceBalance_net` are unaffected.
+- **Editor and PDF render identically** (ADR 0008): the dedicated set row is emphasised in both,
+  and both read the same mutated session.
+
+## Consequences
+- For the two menu modes, `InvoiceSetPricing` stops being a non-mutating render transform over
+  `type == "set"` groups; the grouping/insert/blank/remove is a real mutation in
+  `InvoiceDraftEditService`, keyed on the block. The inline `item.setprice` switch (operation 1)
+  remains the sole `SetItmId`-based, set-item-scoped operation.
+- The previous `admin.setmode` display-flag model for these two modes — persisted `setmode:`
+  `InvoiceOptions` token, "Set-Preisanzeige menu entry disappears while unset", `Build(...)`
+  choosing `ShowPrice` per member at render time — is retired. Because the operation is a
+  one-shot irreversible mutation, there is no persisted display state to toggle. Any residual
+  `setmode:` token must degrade safely (ignored) and is no longer (re-)persisted.
+- New/changed behaviour must be modelled as a server-side delta + calculator/service change and
+  covered by tests (`InvoiceDraftServiceTests`, `InvoiceSetPricingTests`): for each menu mode,
+  assert the inserted set row's value equals the block sum, the total is unchanged, mode 2
+  nulls-but-keeps member rows while mode 3 removes them, and an empty block is a no-op.
+- Reminders follow the identical pattern when/if the same feature is offered there (ADR 0006/0008
+  reminder mirror).
+
+## Alternatives considered
+Each of the following was raised and **explicitly decided against** as part of accepting this
+decision — they are rejected choices, not open options to revisit without a superseding ADR:
+
+- **Keep them as non-mutating display toggles** (the prior design): **explicitly rejected** by the
+  product owner — the set price must be a real, hand-editable value baked into the document, and
+  "Nur Set mit Preis" must actually drop the member lines, not just hide them.
+- **Zero the blanked members' prices instead of nulling them**: **explicitly rejected** — `0` is
+  ambiguous (it prints `0,00 €`), so the frontend could not tell an empty cell from a genuine
+  zero price. Blanked members are set to `null` precisely to make "no price" unambiguous.
+- **Carry the set price on the existing block heading row** instead of a dedicated row:
+  **explicitly rejected** — a separate, individually-editable set row keeps the section-heading
+  semantics intact and gives the user a concrete line to adjust afterwards.
+- **Group by `SetItmId`/`type == "set"` headers like the inline switch:** **explicitly rejected**
+  — the menu modes present each *service request* as one set, independent of any mfr set-item;
+  conflating the two groupings is exactly the ambiguity this decision removes.

Fuchs/Docs/Decisions/0010-mfr-sync-hosted-in-web-app.md

@@ -0,0 +1,78 @@
+---
+status: Accepted
+date: 2026-07-15
+applyTo:
+  - "Fuchs_DataService/**"
+  - "Fuchs/Services/PeriodicHostedService.cs"
+  - "Fuchs/Program.cs"
+supersededBy: ""
+---
+
+# 0010 — MFR ERP sync runs in-process in the web app; Fuchs_DataService is a library
+
+## Context
+`Fuchs_DataService` was a standalone console/Windows Service hosted by **Topshelf**.
+It carried its own `appsettings.json`, its own file-based configuration bootstrap
+(`FdsConfig.Initialize()` reading the file), its own logging provider
+(`FdsLoggerProvider`/`AddFdsLogging`), and a machine-name guard in `Main()` that
+disabled the service on developer PCs. In practice the web app (`Fuchs`) already
+referenced the project, already called `fds.FdsConfig.Initialize(builder.Configuration)`,
+already registered `IFdsMfr`, and already created `FdsMfrClient` via
+`IMfrClientFactory` — so the sync logic and the web app were sharing the same code
+and the same connection strings while the service kept a second, parallel copy of
+configuration/logging/hosting.
+
+Maintaining a separate process, a second `appsettings.json` (duplicating connection
+strings + MFR credentials), Topshelf, and a machine-name guard added drift risk and
+operational overhead for no benefit the web host couldn't provide.
+
+## Decision
+- **`Fuchs_DataService` is now a class library** (no `OutputType Exe`, no Topshelf,
+  no own `appsettings.json`, no `install.bat`/`un-install.bat`, no
+  `System.Configuration.ConfigurationManager`). It contains only the MFR sync
+  logic (`FdsMfr`/`IFdsMfr`, `FdsMfrClient`), the DATEV/zip helpers, `FdsShared`,
+  `FdsDebug`, and `FdsConfig`.
+- **The host owns configuration.** `FdsConfig` keeps only
+  `Initialize(IConfiguration)` (the file-based overload is gone). The Fuchs web app
+  injects its `IConfiguration`; connection strings (`fuchs_fds_ConnectionString`)
+  and MFR credentials (`Fds:MFR_*`, Key Vault-managed) come from Fuchs.
+- **The host owns logging.** `FdsLoggerProvider`/`AddFdsLogging` were removed; the
+  library uses only `ILogger`/`ILoggerFactory` injected from Fuchs's logging
+  (`AddFuchsLogging`). The library depends only on
+  `Microsoft.Extensions.Logging.Abstractions` + `Microsoft.Extensions.Configuration.Binder`.
+- **The sync runs in-process.** `PeriodicHostedService` (the generic
+  multi-job `BackgroundService`) moved to `Fuchs/Services/` and is registered in
+  `Program.cs` as a hosted service. The single `MfrSync` job calls
+  `UpdateIfNecessary_async` → `UpdateRequested_async` → `GetInvoiceFiles_async`.
+- **A config flag replaces the machine-name guard.** Registration is gated by
+  `Fds:SyncEnabled` (default `false` when unset): `true` in production
+  `appsettings.json`, `false` in `appsettings.Development.json`, so developer
+  machines never poll the ERP. Interval (`Fds:ExecutionFrequency_Minutes`, default
+  15) and debug verbosity (`Fds:DebugDetails`) also come from the `Fds` section.
+
+## Consequences
+- One process, one configuration surface, one logging pipeline. The sync inherits
+  the web app's OpenTelemetry, DI, and lifetime automatically.
+- **Instance fan-out is a consideration:** the sync now runs in *every* web instance
+  where `Fds:SyncEnabled` is true. The intranet is deployed single-instance, so this
+  is acceptable; if Fuchs is ever scaled out, gate the sync to a single instance
+  (leader election / dedicated instance flag) to avoid concurrent MFR polling.
+- Enabling/disabling the sync per environment is now a config change, not a
+  redeploy of a separate service.
+- `Fuchs_DataService` is intentionally kept as a separate project (not folded into
+  `Fuchs`) so the sync logic stays isolated and unit-testable; `Fuchs.Tests` covers
+  it via `InternalsVisibleTo`.
+- **The `Squid-Box.SevenZipSharp` native dependency (and the bundled `7z.dll`) was
+  removed** from both `Fuchs_DataService` and `Fuchs`. The only live archive use — the
+  DATEV export — is a plain, unencrypted zip, now produced via the native
+  `OCORE.zip.filesToZipArchive` (`System.IO.Compression`). The 7-Zip-only paths
+  (`.7z`/LZMA2, AES-encrypted archives, extraction, `FastAppend`) had no callers.
+  Trade-off accepted: `System.IO.Compression` cannot produce `.7z` or password/AES
+  archives; if that is ever required, a compression library must be reintroduced.
+
+## Alternatives considered
+- **Native `dotnet` Worker Service (separate process).** Would modernize off
+  Topshelf but keep the duplicate-config/duplicate-logging/second-process problem.
+  Rejected because the web app already hosts everything the sync needs.
+- **Fold the code directly into `Fuchs`.** Rejected to preserve a clean, separately
+  testable sync library and avoid enlarging the web project.

Fuchs/Docs/Decisions/0011-admin-module-system-status.md

@@ -0,0 +1,67 @@
+---
+status: Accepted
+date: 2026-07-16
+applyTo:
+  - "Fuchs/Controllers/IntranetController.Admin.cs"
+  - "Fuchs/Services/SystemStatusService.cs"
+  - "Fuchs/Services/ISystemStatusService.cs"
+  - "Fuchs/Services/SystemStatusModels.cs"
+  - "Fuchs/js/intranet/modules/fis.admin*.js"
+  - "Fuchs/js/intranet/modules/fis.admin.scss"
+supersededBy: ""
+---
+
+# 0011 — Admin module gated on `fds_sys` > 4
+
+## Context
+Operators needed an in-app view of the running deployment's health: which host it
+runs on, whether SQL Server / Azure Key Vault / Azure Blob Storage / the MFR ERP are
+reachable, how the email service is configured (including the dev/test
+`Fuchs:Email:OverrideRecipient` redirect), and a way to send a test email. The
+`StartupSelfTestService` already probes most of these once at startup and writes the
+result to the log — but that is invisible to a logged-in operator and cannot be re-run
+on demand. This is privileged, infrastructure-revealing information (server names,
+account names, connectivity state) that must not be exposed to ordinary users.
+
+## Decision
+- Add an **Admin** module (`admin`) alongside the existing invoice/reminder/report/banking
+  modules, following the same frontend module contract (`init:admin` → `admin/auth`
+  returns `{ manage }` → lazy-load `/web/fis.admin.de.js` + `/web/fis.admin.css` →
+  `init2()`).
+- Access is gated on the caller's **`fds_sys` module authorization being strictly greater
+  than 4** (`fis_getModuleAuth('fds_sys', authuser) > 4`). The menu button is only rendered,
+  and the module script only fetched, for such users; **every** Admin data endpoint
+  additionally re-checks the level server-side (defense in depth) and returns 401 otherwise.
+  `admin/auth` is the sole endpoint that answers for unauthorized users too (it returns
+  `manage: 0`), so the frontend can decide whether to render the module at all.
+- Backend diagnostics live in a new DI-registered `ISystemStatusService` (scoped). It exposes
+  a passive `GetInfo()` snapshot and live, never-throwing connectivity probes
+  (`database`, `keyvault`, `blob`, `mfr`) plus `SendTestEmailAsync`. The test email goes
+  through the normal `IComService` pipeline, so the `OverrideRecipient` safety net applies
+  exactly as for any other outbound mail.
+- The service never returns secrets — only presence flags and non-sensitive values
+  (server/catalog/login name, storage account name, error text). Responses are serialized
+  camelCase to match the frontend's lowercase convention.
+
+## Consequences
+- `fds_sys` is now a security-relevant authorization key: granting it a value > 4 exposes
+  infrastructure status and the ability to send test emails. Provision it deliberately.
+- `SystemStatusService` is intentionally **separate** from `StartupSelfTestService` rather
+  than a shared refactor: the startup service's probe methods are `protected virtual` and its
+  tests override them, so folding both onto one probe surface would have broken that contract.
+  The two therefore duplicate a little probe logic (Key Vault secret read, MFR `GetEntities`,
+  SQL `SELECT`); keep them behaviourally aligned when either changes.
+- New probes (or new status facts) belong in `SystemStatusService` behind the same
+  `SystemProbeResult` / `SystemInfoSnapshot` shapes; add the component id to
+  `SystemStatusService.Components` and a card in `fis.admin.js`.
+- Blob connectivity is checked via a new `IBlobStorageService.CheckConnectivityAsync`
+  (account-info request); it too never throws.
+
+## Alternatives considered
+- **Reuse `StartupSelfTestService` directly.** Rejected — see Consequences; its virtual/overridden
+  probe surface is owned by its tests, and it is a one-shot `BackgroundService`, not a
+  request-scoped query service.
+- **Gate only in the frontend (hide the menu button).** Rejected — the endpoints would still be
+  reachable by crafting the POST. Server-side enforcement on every endpoint is required.
+- **A separate `fds_admin`/new module-auth key.** Rejected — `fds_sys` already models
+  system-level privilege; reusing it avoids a parallel permission to provision.

Fuchs/Docs/Decisions/0012-erechnung-single-pdfa-engine-pipeline.md

@@ -0,0 +1,81 @@
+---
+status: Accepted
+date: 2026-07-17
+applyTo:
+  - "Fuchs/code/FuchsPdf.cs"
+  - "Fuchs/Services/FuchsPdfService.cs"
+  - "Fuchs/Services/InvoiceService.cs"
+  - "Fuchs/Services/ERechnungSettings.cs"
+  - "eRechnungLib/**"
+supersededBy: ""
+---
+
+# 0012 — eRechnung uses a single PDF/A engine (eRechnungLib owns PDF/A-3)
+
+## Context
+ADR 0005 established that invoices are emitted as eRechnung by embedding the CII
+XML into the FuchsPdf-rendered visual PDF via `eRechnungLib.ToZugferd(...)`.
+
+Two hard requirements then surfaced: the emitted invoice must (a) satisfy the
+**ZUGFeRD 2.4 / Factur-X** standard for **DATEV** ingestion, and (b) be a
+**formally verifiable PDF/A-3** (veraPDF-clean).
+
+A conflict became apparent in the rendering pipeline. `FuchsPdf.DocToPdfBytes`
+post-processes its MigraDoc/PdfSharp output to **PDF/A via Spire**
+(`OCORE…pdfAFileContent`). `eRechnungLib`'s `FacturXPdfBuilder` **also** produces
+a PDF/A layer (raises to PDF 1.7, writes `pdfaid` XMP, adds an sRGB output
+intent, embeds `factur-x.xml` in `/AF`). Feeding a Spire-made PDF/A into
+eRechnungLib stacks **two** PDF/A conversions → duplicate/*conflicting* output
+intents and `pdfaid` markers, which veraPDF rejects. Spire's output is also
+PDF/A-1/2 and does **not** carry the `/AF` associated-file structure ZUGFeRD
+requires (PDF/A-3).
+
+Separately, `eRechnungLib` shipped **no** sRGB ICC profile, so its output intent
+was silently omitted (`PDFA-ICC` warning) — never formally PDF/A-3 conformant.
+
+## Decision
+- **eRechnungLib is the single PDF/A engine for eRechnung output.** The invoice
+  visual PDF is rendered by `FuchsPdf` **without** the Spire PDF/A step and handed
+  to `eRechnungLib.ToZugferd(ZugferdProfile.EN16931, rawPdfBytes)`, which owns the
+  one PDF/A-3 conversion and embeds the CII XML. The render-only path is
+  `FuchsPdf.DocToPdfBytesRaw` / `IPdfService.DocToPdfBytesRaw` (fonts still
+  embedded via `OCOREFontResolver`, no PDF/A post-processing).
+- **Spire stays only for on-screen preview rasterisation** (`DocToImageCollection`
+  / `BytesToImageCollection` for `sprep`/`sedit`). It is **not** part of the
+  eRechnung file's PDF/A path. `DocToPdfBytes` (render + Spire PDF/A) is unchanged
+  and remains the path for non-eRechnung documents (e.g. reminders).
+- **A bundled sRGB ICC profile is required.** `eRechnungLib` ships
+  `Resources/Color/sRGB.icc` (sRGB IEC61966-2.1) so the PDF/A output intent is
+  always attached. A caller may override it per conversion via
+  `ConversionOptions.IccProfile`.
+- **Profile is EN 16931.** MINIMUM / BASIC WL are not offered for real invoices —
+  DATEV needs at least EN 16931 (COMFORT) for full booking.
+- **Formal conformance is verified by an external online service** (veraPDF for
+  PDF/A-3 + a ZUGFeRD/EN 16931 validator), behind the configurable
+  `Fuchs:ERechnung:Validation:ServiceUrl` seam. Until the URL is provisioned,
+  verification reports "not configured / skipped".
+
+## Consequences
+- The eRechnung invoice PDF and a plain Spire PDF/A must never both be produced
+  for the same document — pick the render-only path when emitting eRechnung.
+- The incoming visual PDF must itself be PDF/A-friendly (fonts embedded —
+  handled; letterhead images must be **RGB, not CMYK**; transparency is allowed
+  because we target PDF/A-**3**).
+- `Fuchs:ERechnung:Enabled` gates emission and stays `false` until the
+  `FdsInvoiceData` → `eRechnungLib.Model.Invoice` mapping is wired (the ADR 0005
+  follow-up). Open item for that mapping: the buyer address is currently a
+  free-text block (`SendToAddress`); EN 16931 needs **structured** buyer
+  fields (name/postcode/city/country, VAT id), so structured customer master
+  data must feed the mapping. Seller data (currently hard-coded in `FuchsPdf`:
+  name, address, tax number, IBAN/BIC) must be lifted into the seller model.
+- `Fuchs.csproj` must add a project reference to `eRechnungLib` when the flow is
+  wired (not present yet).
+
+## Alternatives considered
+- **Keep Spire PDF/A and have eRechnungLib only embed the XML:** rejected — Spire
+  produces the wrong PDF/A part (1/2, no `/AF`) and a second conversion collides
+  with eRechnungLib's own output intent/XMP, failing veraPDF.
+- **Drop Spire entirely:** rejected — Spire is still needed to rasterise PDFs to
+  the on-screen invoice/reminder preview images; PdfSharp/eRechnungLib cannot.
+- **Ship no ICC and rely on callers:** rejected — formal PDF/A-3 requires an
+  output intent; bundling a profile makes conformance the default.

Fuchs/Docs/Decisions/README.md

@@ -0,0 +1,71 @@
+# Decisions
+
+This folder holds **Architecture Decision Records (ADRs)** — short, immutable
+records of a specific technical choice, why it was made, and what it implies
+going forward.
+
+## What belongs here
+
+A decision, not a how-to. If it answers "why do we do X this way, and what
+else did we consider," it's a decision. If it explains "how subsystem X
+currently works," that belongs in [`../Concepts`](../Concepts/README.md)
+instead (and a decision often triggers a concept doc to be created/updated).
+
+## File naming
+
+`NNNN-kebab-case-title.md`, four-digit zero-padded, sequential across the
+whole folder (`0001-...`, `0002-...`). Never reuse or renumber.
+
+## Required YAML frontmatter
+
+Every decision file starts with:
+
+```yaml
+---
+status: Accepted        # Proposed | Accepted | Superseded
+date: 2026-07-03         # date the decision was accepted
+applyTo:                 # glob(s) — files/areas this decision governs
+  - "Fuchs/Notifications/**"
+supersededBy: ""         # filename of the decision that replaced this one, if any
+---
+```
+
+**Agents (Claude, Copilot, Codex) must scan the YAML frontmatter of every file
+in this folder first** (cheap — no need to read the body) and only read the
+full body of decisions whose `applyTo` glob matches the files they're about
+to touch, or whose subject is otherwise clearly relevant to the task. This
+keeps decision-following cheap even as the folder grows.
+
+## Body template
+
+```markdown
+# NNNN — Title
+
+## Context
+What problem/situation forced a choice.
+
+## Decision
+What was decided, stated plainly.
+
+## Consequences
+What this implies for future code — constraints, follow-ups, trade-offs
+accepted knowingly.
+
+## Alternatives considered
+Options that were rejected and why (optional but preferred).
+```
+
+## Rules
+
+- **Decisions are immutable once `Accepted`.** Do not edit the Decision/
+  Consequences of an existing file to reverse it. Instead, write a new
+  decision, set its `applyTo`/subject accordingly, and set the old file's
+  `status: Superseded` + `supersededBy: NNNN-new-file.md`.
+- **Follow existing decisions.** Before implementing anything in an area
+  covered by an `Accepted` decision, read it and conform to it. If you
+  believe a decision is wrong, raise it with the user rather than silently
+  deviating.
+- **Capture new decisions as they happen.** Whenever the user (or the code
+  you're writing) settles a non-obvious architectural or cross-cutting
+  choice — not a routine implementation detail — add a decision here in the
+  same change, and create/update the matching concept doc in `../Concepts`.

Fuchs/Docs/EVAL_live_invoice_editing.md

@@ -1,5 +1,17 @@
 # Evaluation — Backend-cached invoice editing over SignalR
 
+> **⚠️ Superseded (2026-07-10).** This note's recommendation (keep the editor
+> stateless; do **not** build the SignalR/server-cached model) was reversed by the
+> product owner. Invoice draft editing is now backend-authoritative over an in-memory
+> cache — see **ADR
+> [`Decisions/0006-backend-authoritative-draft-editing.md`](Decisions/0006-backend-authoritative-draft-editing.md)**,
+> [`Decisions/0007-targeted-draft-signalr-groups.md`](Decisions/0007-targeted-draft-signalr-groups.md)
+> and the concept doc [`Concepts/live-draft-editing.md`](Concepts/live-draft-editing.md).
+> The analysis below is retained for the historical rationale and the risks it flagged
+> (server-held state, scaling/backplane, reconnect) — which the new design addresses or
+> accepts explicitly as documented limitations.
+
+
 **Idea (as proposed):** hold invoices that users are editing in a **server-side
 cache**, keep a **SignalR / WebSocket** connection open, apply each front-end
 change **in the backend**, and **push the recomputed state back** to the browser.

Fuchs/Docs/INVOICE_LIFECYCLE.md

@@ -90,12 +90,20 @@ payload; see `EVAL_live_invoice_editing.md` for the rationale.
 ### 4.1 What the user can change
 - **Line items** — quantities, prices, notes, combine into one sum
   (`$inv.rendersrq`, `$inv.quantChange`).
-- **Recipient fields** — invoice title, address, email, provision
-  location/period (inline edit fields, `fm(...)` helper in `fis.inv_shared.js`).
+- **Recipient fields** — invoice title, email, provision location/period (inline
+  edit fields, `fm(...)` helper in `fis.inv_shared.js`). The **recipient address**
+  is edited via a **structured dialog** (`$inv.eAddress`: name, street, PLZ, city,
+  country, optional VAT id) prefilled from `fds__prepInvoice`'s `invoiceaddressData`;
+  it drives the EN 16931 eRechnung and composes the free-text `SendToAddress` for the
+  PDF (see [`Concepts/erechnung-output.md`](Concepts/erechnung-output.md)). The **service
+  date/period** (Leistungsdatum/-zeitraum) is likewise a structured German-date dialog
+  (`$inv.eProvisionPeriod`) — a single date or a from/to range — mapped to BT-72 / BG-14.
 - **§13b reverse-charge** toggle (`$inv.sp13b`) — suppresses VAT lines/columns.
 - **Set-pricing display mode** (`$inv.ssetmode` / `setSetmode`) — `SetPrice`
-  (default) / `ItemPrices` / `SetOnly`; see `INVOICE_SET_PRICING.md`. Purely
-  presentational — totals never change.
+  (default) / `SetOnly`; see `INVOICE_SET_PRICING.md`. Purely presentational
+  while the set header itself has no own price; once a set is converted via
+  the item switch (`item.setprice`), the conversion is one-way and totals
+  recompute from that point on.
 - **Contact person** for the invoice (`$inv.sctp`, stored in `CustomValues`).
 
 All of this recalculates client-side totals live via the `fds.inv` event
@@ -122,7 +130,7 @@ On the server, `RegisterInvoiceAsync` (in `InvoiceService`) turns the posted
 JSON into SQL parameters and calls, in one batch:
 - **New invoice**: `fds__createInvoice` (allocates the `Id`, returns a fresh
   row) → `fds__createInvoice_Details` (service net/VAT + `InvoiceOptions`,
-  e.g. `setmode:itemprices`, `§13b`).
+  e.g. `setmode:setonly`, `§13b`).
 - **Existing draft**: `fds__setInvoice` (same parameter set, updates in place)
   → `fds__createInvoice_Details` again.
 
@@ -337,9 +345,18 @@ flowchart TD
 
 ## 10. Key invariants worth remembering
 
-- **Stateless editor**: every preview/save/finalise call re-posts the full
-  `invc` JSON; the server never holds a partial invoice in memory or session
-  between requests (see `EVAL_live_invoice_editing.md`).
+> **⚠️ Updated (2026-07-10):** the "stateless editor" invariant below describes the
+> **legacy** draft-editing flow. Invoice draft editing is being moved to a
+> **backend-authoritative** model where the server holds the draft in an in-memory
+> cache (the single source of truth), the browser posts single edits and re-fetches on
+> a SignalR signal, and totals are computed server-side. See ADR
+> [`Decisions/0006-backend-authoritative-draft-editing.md`](Decisions/0006-backend-authoritative-draft-editing.md)
+> and [`Concepts/live-draft-editing.md`](Concepts/live-draft-editing.md). Finalise/email
+> (§5–§6) are unchanged. The remaining invariants below still hold.
+
+- **Stateless editor** *(legacy — see the note above; superseded by ADR 0006)*: every
+  preview/save/finalise call re-posts the full `invc` JSON; the server never holds a
+  partial invoice in memory or session between requests (see `EVAL_live_invoice_editing.md`).
 - **Totals come from the registration, not the rendered lines**: `sms.ttn`
   /`sms.ttb` (posted) become `InvoiceBalance`/`InvoiceBalance_net`; display
   mode (set pricing) never changes what the customer owes.
@@ -349,6 +366,10 @@ flowchart TD
 - **Draft vs. final changes the rendered PDF**: draft = watermark overlay, no
   GiroCode; final = no watermark, GiroCode payment QR added when there's a
   positive balance.
+- **Final invoices can be emitted as eRechnung**: when `Fuchs:ERechnung:Enabled`,
+  the final PDF is a ZUGFeRD/Factur-X **PDF/A-3 hybrid** (eRechnungLib embeds the
+  CII XML into the render-only visual PDF; any failure falls back to the plain
+  PDF/A). Off by default. See [`Concepts/erechnung-output.md`](Concepts/erechnung-output.md).
 - **Email is best-effort and tracked**: `IsSent` is only set `true`
   automatically after a *successful* send; a failed send still leaves a
   correctly finalised, stored invoice that staff can resend or mark sent

Fuchs/Docs/INVOICE_SET_PRICING.md

@@ -1,24 +1,54 @@
-# Invoice "Set" Pricing — Design & Front-/Back-end Contract
+# Invoice "Set" Pricing — Design & Front-/Back-end Contract
 
-Customer requirement: items declared as a **set** in `[dbo].[mfr__items]`
-(`[Type] = 'set'`) should normally be shown as a single **set price** on the
-invoice instead of being broken up into their member items and summed.
+> Governed by ADR [0009](Decisions/0009-block-setprice-modes-are-irreversible-mutations.md)
+> (the two menu modes) and ADR [0008](Decisions/0008-invoices-and-reminders-fully-backend-authoritative.md)
+> (everything server-side, PDF == editor). ADR 0009 **redefined** the two menu modes from the
+> reversible, non-mutating display toggles this document previously described into irreversible,
+> per-service-request-block mutations — the text below reflects the redefinition.
 
-Three display modes (switchable in the invoice editor):
+There are **three** separate set-price operations. They fall into two families that must not be
+confused, because they group items by different keys and differ in whether they mutate the data:
 
-| Mode | Set line | Member items | Use as |
-|---|---|---|---|
-| **SetPrice** (default) | shown **with price** | shown **without price** | the new default |
-| **ItemPrices** | shown as a heading **without price** | shown **with price** | the previous behaviour |
-| **SetOnly** | shown **with price** | **removed** | compact |
+| # | Operation | Trigger | Grouped by | Effect |
+|---|---|---|---|---|
+| **1** | **Set-item switch** | row context button on a single `type == "set"` item (`$inv.toSetPrice`), shown only when it has a `SetItmId` | `SetItmId` (the mfr set-item and its members) | sums members onto the set header, sets the members' prices to `null` — **one-way mutation** |
+| **2** | **"Set mit Preis"** | editor menu ("Set-Preisanzeige") | **`ServiceRequestId`** (the whole block) | inserts a dedicated **set row** per block (block sum as its price) and sets every item's price to **`null`** (items shown **without price**) — **irreversible mutation** |
+| **3** | **"Nur Set mit Preis"** | editor menu ("Set-Preisanzeige") | **`ServiceRequestId`** (the whole block) | inserts the dedicated **set row** per block and **removes** every item line from the block — **irreversible mutation** |
 
-> **Totals are unaffected.** The invoice total is taken from the registration
-> balance (`InvoiceBalance` / `InvoiceBalance_net`), not by summing the rendered
-> lines, so switching modes is purely presentational. The set price always
-> equals the sum of its members (computed as a fallback when the set header
-> carries no own price).
+Only operation **1** reads `SetItmId`. Operations **2** and **3** ignore it entirely; their only
+grouping key is the service request (the editor tbody block). See "All set-price functions" below
+for the full breakdown.
 
-## Back-end (implemented + unit-tested)
+> **The two menu modes are irreversible data changes, not display toggles.** Choosing "Set mit
+> Preis" or "Nur Set mit Preis" rewrites the block's items in the authoritative, server-cached
+> draft session (`InvoiceDraftSession.Req` — the "cache dataset"): a dedicated set row is inserted
+> and members have their price set to `null` (mode 2) or are deleted (mode 3). There is **no**
+> reversible toggle and **no** persisted `admin.setmode` render flag driving grouping. The only
+> ways back are discarding the draft (reloads the DB state) or hand-editing the resulting rows —
+> the set row is a real, editable line item precisely so the user can adjust the set value
+> afterwards.
+
+> **`ItemPrices` / `admin.setmode` display-flag model was removed.** The earlier design persisted
+> a `setmode:<mode>` token in `InvoiceOptions` and re-rendered set-item groups per that flag at
+> render time (`InvoiceSetPricing.Build`). Under ADR 0009 the two menu modes are one-shot
+> mutations, so there is no display state to persist or toggle. A stale `setmode:`/`itemprices`
+> token degrades safely (ignored) and is never (re-)persisted.
+
+> **Totals are unaffected.** The invoice total is taken from the registration balance
+> (`InvoiceBalance` / `InvoiceBalance_net`), not by summing the rendered lines. Each operation
+> conserves the total: the inserted set row's value equals the sum of the items it blanks (mode 2)
+> or removes (mode 3), and the set-item switch (mode 1) writes exactly the members' sum onto the
+> header.
+
+## Back-end
+
+> **Migration status (ADR 0009).** The code below still reflects the previous
+> `admin.setmode` + `InvoiceSetPricing.Build` **display-mode** implementation for
+> functions 2 & 3. Under ADR 0009 those two functions become per-block mutations in
+> `InvoiceDraftEditService` (insert set row + blank/remove members); the render-time
+> `Build`/`ModeFromInvoiceOptions`/`setmode` display path for them is being retired.
+> Function 1 (`ApplyItemSetPrice`) is unaffected. Update this section as the
+> migration lands so it stays a faithful description of the code.
 
 - `Fuchs/code/InvoiceSetPricing.cs` — the authoritative transformation:
   `SetDisplayMode` + `Build(items, mode)` → ordered `InvoiceSetLine`s, each with
@@ -34,15 +64,15 @@ Three display modes (switchable in the invoice editor):
 Wired in `Fuchs/js/intranet/modules/fis.inv_shared.js` (bundled to
 `wwwroot/web/fis.inv.de.js` via gulp `min:js`):
 
-1. **Mode** — a 3-way switch (`$inv.ssetmode`, menu entry `setm`, label
-   `$ict.setm`) writes the choice onto `admin.setmode`
-   (`setprice` | `itemprices` | `setonly`). The back-end
-   `FdsInvoiceData.BuildInvoiceOptions` turns that into the
-   `setmode:<mode>` token inside `@InvoiceOptions` (default `setprice` omitted),
-   persisted by `fds__createInvoice_Details` and read back by
-   `InvoiceSetPricing.ModeFromInvoiceOptions`. This rides the **same `admin`
-   channel as `§13b`** (the posted payload is `{admin, req, sms, new}` — `inv`
-   is not sent).
+1. **Menu modes** — the "Set-Preisanzeige" menu (`$inv.ssetmode` → `$inv.setSetmode`,
+   menu entry `setm`, label `$ict.setm`) offers "Set mit Preis" and "Nur Set mit
+   Preis". Selecting one posts a **mutating delta** (grouped by service-request
+   block) to `inv/dpatch`; the server rewrites the block's items in the cached
+   session (inserts the set row, blanks or removes members) and pushes the new
+   state back via `draftReady`/`dstate`. The browser performs **no** grouping or
+   pricing math (ADR 0008/0009) — it only posts the chosen mode and re-renders the
+   server's `req`/`sums`. There is no persisted `admin.setmode` display flag for
+   these two modes.
 
 2. **Item shape** — `$inv.invSumUpdate` now posts each request block's
    `items[]` in the back-end contract shape via `$inv.itemToContract`:
@@ -51,12 +81,20 @@ Wired in `Fuchs/js/intranet/modules/fis.inv_shared.js` (bundled to
    `FdsInvoiceData.InvoiceItems` does not read — so line items never reached the
    C# PDF. This change closes that gap for **all** invoices, not just sets.)
 
-3. **Set flags** — `invSumUpdate` tags items as it builds `items[]`: an item with
-   `type === 'set'` is a header (`id` = its set id); the **following items in the
-   same block become its members** (`setId` = the header's id) until the next set
-   header. `mfr__items` has a `Type='set'` header but **no explicit member link**,
-   so this "header claims the following items in its block" rule is the convention
-   — adjust in `invSumUpdate` if mfr later exposes a real grouping.
+3. **Set flags (function 1 only)** — `invSumUpdate` tags items as it builds `items[]`:
+   an item with `type === 'set'` is a header (`id` = its set id); a member item's
+   `setId` is taken directly from the server-computed `SetItmId` field on the row
+   (`rrx.SetItmId`, populated by `fds__prepInvoice`'s `[SetItmID]` window function,
+   anchored on the still-unconverted, zero-priced `'set'` header that owns it) —
+   **not** re-derived from row order in the browser. `mfr__items` itself still has no
+   explicit member link; `fds__prepInvoice` computes `SetItmId` per request from the
+   item list, so only items the server actually attributes to a set are tagged, and
+   unrelated items following a set in the list are never swept in. The header row's
+   own `SetItmId` self-references its own id (rather than being `null`); it is
+   explicitly excluded from being its own member both here (`sid !== citem.id`) and
+   in `InvoiceDraftEditService.ApplyItemSetPrice`. These flags feed **only** the
+   set-item switch (function 1); the two menu modes (functions 2 & 3) ignore
+   `SetItmId` and group by service-request block.
 
 ### Editor → backend field normalization (`$inv.invcPayload`)
 The editor's internal model keeps the long-standing key names, but the migrated C#
@@ -80,20 +118,95 @@ no per-rate `vat_*` keys.
   `sms.vat`, so non-19 % rates are stored correctly. Single-rate procs still store only
   the highest rate.
 
-The editor's running **total stays the member sum in every mode**, matching the
-registration balance — switching modes is purely presentational.
+The editor's running **total is unaffected by any set-price operation**, matching
+the registration balance — each operation conserves the total (the set row's value
+equals the members it blanks/removes; the set-item switch writes exactly the
+members' sum onto the header).
 
-### Why the switch lives in the editor
-Set grouping is only known where the request/item tree is rendered (front-end).
-The back-end intentionally stays the single, tested authority for *how* a chosen
-mode maps to printed lines, so the editor only needs to pick the mode and tag the
-items — it does not re-implement the pricing rules.
+### Why the trigger lives in the editor
+The choice of *when* to apply a set-price operation is only known where the invoice
+is being composed (front-end), but the operation itself is executed **server-side**
+against the cached draft session — the editor merely names the target (a set-item
+`Ref` for function 1, or the chosen menu mode for functions 2 & 3) and re-renders
+the server's result. The back-end stays the single, tested authority for how each
+operation rewrites the lines; the editor never re-implements the grouping, the
+per-block aggregation, or the pricing rules (ADR 0008/0009).
+
+## All set-price functions: before/after comparison
+
+There are **three** distinct functions, and all three are **mutations** of the
+authoritative cached draft session (`InvoiceDraftSession.Req`) — none is a
+transient, freely-reversible view flag. They differ in what they group by and
+what they touch:
+
+- **Function 1 — the set-item switch** (`item.setprice`) groups by `SetItmId`
+  (one mfr set-item and its members) and is triggered per set row.
+- **Functions 2 & 3 — the two menu modes** ("Set mit Preis" / "Nur Set mit
+  Preis") group by `ServiceRequestId` (the whole block), ignore `SetItmId`
+  entirely, and are triggered once from the "Set-Preisanzeige" menu.
+
+Only function 1 reads `SetItmId`. All three are one-way; the only escape hatch
+is discarding the draft or hand-editing the resulting rows.
+
+### 1. The set-item switch (`item.setprice` patch, single set, mutating)
+
+Triggered from the invoice editor's row context menu (`$inv.toSetPrice`), applied
+server-side by `InvoiceDraftEditService.ApplyItemSetPrice`. The context button is
+shown — and the operation available — **only** on a row that is `type == "set"`
+**and** carries a `SetItmId` (and is still unconverted, own price `0`); a row
+missing either condition never offers it. It gives a set-item its "own price": the
+members' values are summed onto the header and the members' prices are set to
+`null` (empty cell, excluded from the sum — not `0`). This
+conversion is **one-way** — there is no patch to move a converted set back to
+separately-priced members; the user would re-edit the individual line prices by
+hand. It is the **only** function keyed on `SetItmId`.
+
+| Aspect | Before the switch | After the switch |
+|---|---|---|
+| Set header item (`type == "set"`, `id == Ref`) price | `0` (zero-priced, as delivered by `fds__prepInvoice`) | Price fields (`total_net`/`v`/`vt` + VAT amounts `vv`/`vs`/`vsv`) replaced by the sum of all its members' corresponding values |
+| Member items (`SetItmId == Ref`, excluding the header itself) | Each shows its own individual `total_net` / VAT amounts | Each price field is set to **`null`** (`v`/`vt`/`vv`/`vs`/`vsv` all `null`, not `0`) → renders an **empty** price/total cell and is excluded from the sum; the row itself stays in the list |
+| Membership determination | N/A — membership already fixed by the server (`fds__prepInvoice`'s `[SetItmID]` window function) | **Unchanged** — the switch only sums/nulls the items the server already tagged; it never re-derives or reassigns `SetItmId` |
+| Items **not** tagged with this header's `SetItmId` (e.g. unrelated items following the set in the same block) | Untouched | **Still untouched** — never swept in, regardless of row order/position |
+| Draft version / history | — | Version bumped by one; an `item.setprice` history entry recorded with old/new header value |
+| Invoice total (`Sums.TotalNet`/`TotalGross`) | Sum of all individual item prices (header 0 + each member's own price) | **Unchanged** — same total, because the header received exactly the sum of its members |
+| Idempotency / no-ops | `Ref` unknown, or `Ref` does not point at a `type == 'set'` header → **no-op**: no version bump, no history entry | Same guard still applies after conversion — re-issuing the patch against a non-header `Ref` remains a no-op |
+
+### 2 & 3. The two menu modes (per service-request block, mutating)
+
+Triggered once from the editor's "Set-Preisanzeige" menu (`$inv.ssetmode` →
+`$inv.setSetmode`) and applied server-side per **service-request block**
+(`ServiceRequestId`), independent of any `type == "set"` item or `SetItmId`.
+Both are **irreversible** and rewrite the block's items in the cached session.
+
+For each block, a dedicated, emphasised **set row** is inserted (see "The
+dedicated set row" below) carrying the block's aggregated value as its price;
+then, depending on the mode, the block's original items are either blanked or
+removed:
+
+| Aspect | **"Set mit Preis"** (mode 2) | **"Nur Set mit Preis"** (mode 3) |
+|---|---|---|
+| Grouping key | `ServiceRequestId` (block) | `ServiceRequestId` (block) |
+| Inserted set row | one per block, price = block's aggregated net (+ VAT/service splits) | one per block, same value |
+| Original item rows | **kept**, but each price field (`v`/`vt`/`vv`/`vs`/`vsv`) is set to **`null`** (not `0`) → renders an **empty** price/total cell and is excluded from the block sum | **removed** from the block entirely |
+| `SetItmId` | ignored | ignored |
+| Reversibility | irreversible (discard draft or hand-edit) | irreversible (discard draft or hand-edit) |
+| Invoice total | **unchanged** — the set row's value equals the sum of the block's members it blanks | **unchanged** — the set row's value equals the sum of the removed lines |
+| Empty block | no-op | no-op |
+
+### The dedicated set row
+
+Both menu modes insert a **real, editable line item** (its own id, rendered
+emphasised in the editor and the PDF), not a reused block-heading row and not a
+render-only overlay. Because it is a genuine row in the cached dataset, the user
+can adjust the set value afterwards with an ordinary item edit — that hand-edit
+is the intended and only "undo" for the conversion (ADR
+[0009](Decisions/0009-block-setprice-modes-are-irreversible-mutations.md)).
 
 ## Persistence note
-Draft/preview PDFs render straight from the posted `invc` JSON, so the contract
-works end-to-end for previews and creation. `setmode` persists via
-`InvoiceOptions`; the finalised document is rendered once and stored as a file, so
-re-rendering from line items is not needed for correctness. Persisting the
-per-item `type`/`setId` flags (an SSDT + `fds__createInvoice_Details` change) is
-only required if a finalised invoice must be **re-generated** from stored items in
-a different mode later — not done here.
+Draft/preview PDFs render straight from the cached draft session, so the contract
+works end-to-end for previews and creation. The two menu modes bake their result
+directly into the session's items (a set row plus blanked/removed members), so no
+`setmode:` display token is needed or persisted; the finalised document is
+rendered once and stored as a file. Persisting the per-item `type`/`setId` flags
+(an SSDT + `fds__createInvoice_Details` change) is only required if a finalised
+invoice must be **re-generated** from stored items later — not done here.

Fuchs/Docs/Neuerungen_Fuchs_Intranet.html

@@ -0,0 +1,489 @@
+<!DOCTYPE html>
+<html lang="de">
+<head>
+<meta charset="UTF-8">
+<meta name="viewport" content="width=device-width, initial-scale=1.0">
+<title>Fuchs Intranet — Das ist neu</title>
+<style>
+  :root{
+    --blue:#1b4379;        /* $fuchs_blau */
+    --blue-2:#2a5da3;
+    --accent:#56a532;      /* $fuchs_akzent */
+    --accent-2:#74c14a;
+    --ink:#12243f;
+    --ink-2:#1a2f52;
+    --paper:#f4f6fa;
+    --card:#ffffff;
+    --text:#1c2430;
+    --muted:#586172;
+    --line:#e3e8f0;        /* near $fuchs_lightgray */
+    --green:#56a532;
+    --shadow:0 18px 50px -20px rgba(18,36,63,.35);
+  }
+  *{box-sizing:border-box}
+  html{scroll-behavior:smooth}
+  body{
+    margin:0;
+    font-family:"Segoe UI",system-ui,-apple-system,Roboto,Helvetica,Arial,sans-serif;
+    color:var(--text);
+    background:var(--paper);
+    line-height:1.6;
+    -webkit-font-smoothing:antialiased;
+  }
+  .wrap{max-width:1080px;margin:0 auto;padding:0 24px}
+
+  /* ---------- HERO ---------- */
+  .hero{
+    position:relative;
+    color:#fff;
+    background:
+      radial-gradient(1200px 500px at 80% -10%, rgba(86,165,50,.38), transparent 60%),
+      radial-gradient(900px 500px at 0% 10%, rgba(42,93,163,.50), transparent 55%),
+      linear-gradient(160deg,#1b3a63 0%, #12243f 60%, #0b1727 100%);
+    overflow:hidden;
+    border-bottom:1px solid rgba(255,255,255,.06);
+  }
+  .hero::after{
+    content:"";position:absolute;inset:0;
+    background:linear-gradient(180deg,transparent 60%,rgba(0,0,0,.25));
+    pointer-events:none;
+  }
+  .hero .wrap{position:relative;z-index:2;padding:78px 24px 92px}
+  .eyebrow{
+    display:inline-flex;align-items:center;gap:9px;
+    font-size:.8rem;font-weight:600;letter-spacing:.14em;text-transform:uppercase;
+    color:var(--accent-2);
+    background:rgba(86,165,50,.12);
+    border:1px solid rgba(86,165,50,.28);
+    padding:7px 15px;border-radius:100px;
+  }
+  .eyebrow .dot{width:8px;height:8px;border-radius:50%;background:var(--accent);box-shadow:0 0 14px var(--accent)}
+  h1{
+    font-size:clamp(2.1rem,5vw,3.6rem);
+    line-height:1.08;margin:22px 0 16px;font-weight:800;letter-spacing:-.02em;
+  }
+  h1 .grad{
+    background:linear-gradient(92deg,var(--accent-2),#fff 70%);
+    -webkit-background-clip:text;background-clip:text;color:transparent;
+  }
+  .lede{font-size:clamp(1.05rem,2.2vw,1.28rem);color:#c7cdda;max-width:640px;margin:0}
+  .hero-meta{
+    display:flex;flex-wrap:wrap;gap:26px;margin-top:38px;
+    padding-top:26px;border-top:1px solid rgba(255,255,255,.1);
+  }
+  .hero-meta div{min-width:120px}
+  .hero-meta b{display:block;font-size:1.7rem;font-weight:800;color:#fff}
+  .hero-meta span{font-size:.86rem;color:#98a1b3}
+
+  /* ---------- SECTIONS ---------- */
+  section{padding:64px 0}
+  .section-head{max-width:680px;margin-bottom:40px}
+  .section-head .kicker{color:var(--accent);font-weight:700;font-size:.82rem;letter-spacing:.12em;text-transform:uppercase}
+  h2{font-size:clamp(1.6rem,3.4vw,2.3rem);margin:10px 0 12px;font-weight:800;letter-spacing:-.02em}
+  .section-head p{color:var(--muted);font-size:1.06rem;margin:0}
+
+  /* ---------- FEATURE CARDS ---------- */
+  .grid{display:grid;grid-template-columns:repeat(auto-fit,minmax(300px,1fr));gap:22px}
+  .card{
+    background:var(--card);
+    border:1px solid var(--line);
+    border-radius:18px;
+    padding:28px 26px;
+    box-shadow:var(--shadow);
+    position:relative;
+    transition:transform .25s ease, box-shadow .25s ease;
+    overflow:hidden;
+  }
+  .card::before{
+    content:"";position:absolute;top:0;left:0;right:0;height:3px;
+    background:linear-gradient(90deg,var(--accent),var(--accent-2));
+    opacity:.9;
+  }
+  .card:hover{transform:translateY(-5px);box-shadow:0 26px 60px -24px rgba(20,24,33,.45)}
+  .card .ico{
+    width:48px;height:48px;border-radius:13px;display:grid;place-items:center;
+    background:linear-gradient(150deg,rgba(86,165,50,.16),rgba(116,193,74,.06));
+    border:1px solid rgba(86,165,50,.22);
+    font-size:1.5rem;margin-bottom:16px;
+  }
+  .card h3{margin:0 0 8px;font-size:1.18rem;font-weight:700}
+  .card p{margin:0;color:var(--muted);font-size:.97rem}
+  .card .tag{
+    display:inline-block;margin-top:16px;font-size:.75rem;font-weight:600;
+    color:var(--accent);background:rgba(86,165,50,.09);
+    border:1px solid rgba(86,165,50,.2);padding:4px 11px;border-radius:100px;
+  }
+
+  /* ---------- BEFORE / AFTER ---------- */
+  .compare{background:linear-gradient(180deg,#fff,#f2f4f9);border-top:1px solid var(--line);border-bottom:1px solid var(--line)}
+  .table-scroll{overflow-x:auto;border-radius:16px;box-shadow:var(--shadow);border:1px solid var(--line)}
+  table{border-collapse:collapse;width:100%;min-width:640px;background:#fff}
+  th,td{text-align:left;padding:16px 20px;border-bottom:1px solid var(--line);vertical-align:top}
+  thead th{background:var(--ink);color:#fff;font-weight:600;font-size:.92rem;letter-spacing:.01em}
+  thead th:first-child{border-top-left-radius:16px}
+  thead th:last-child{border-top-right-radius:16px}
+  tbody tr:last-child td{border-bottom:none}
+  td.feat{font-weight:700;color:var(--ink);width:24%}
+  td.old{color:var(--muted)}
+  td.old::before{content:"✕ ";color:#c4453b;font-weight:700}
+  td.new{color:#1c2733}
+  td.new::before{content:"✓ ";color:var(--green);font-weight:700}
+  tbody tr:nth-child(even){background:#fafbfe}
+
+  /* ---------- SPOTLIGHT ---------- */
+  .spot{display:grid;grid-template-columns:1.05fr .95fr;gap:38px;align-items:center}
+  .spot-card{
+    background:linear-gradient(160deg,var(--ink),var(--ink-2));
+    color:#fff;border-radius:22px;padding:34px;box-shadow:var(--shadow);
+    border:1px solid rgba(255,255,255,.07);
+  }
+  .spot-card h3{margin:0 0 14px;font-size:1.35rem}
+  .spot-card ul{margin:0;padding:0;list-style:none}
+  .spot-card li{position:relative;padding:9px 0 9px 30px;color:#cdd3df;border-bottom:1px dashed rgba(255,255,255,.09)}
+  .spot-card li:last-child{border-bottom:none}
+  .spot-card li::before{content:"→";position:absolute;left:0;color:var(--accent-2);font-weight:800}
+  .spot-text h2{margin-top:0}
+  .spot-text p{color:var(--muted)}
+  .chip{display:inline-block;font-size:.78rem;font-weight:600;color:var(--accent);background:rgba(86,165,50,.1);border:1px solid rgba(86,165,50,.22);padding:5px 12px;border-radius:100px;margin-bottom:14px}
+
+  /* ---------- KEY USER BOX ---------- */
+  .keyuser{background:var(--ink);color:#fff}
+  .keyuser .section-head p{color:#a7afbe}
+  .ku-grid{display:grid;grid-template-columns:repeat(auto-fit,minmax(240px,1fr));gap:20px}
+  .ku{
+    background:rgba(255,255,255,.04);border:1px solid rgba(255,255,255,.09);
+    border-radius:16px;padding:24px;
+  }
+  .ku h3{margin:0 0 8px;font-size:1.05rem;color:#fff}
+  .ku h3 span{color:var(--accent-2)}
+  .ku p{margin:0;color:#a7afbe;font-size:.93rem}
+
+  /* ---------- EDITOR STEPS ---------- */
+  .steps{display:grid;grid-template-columns:repeat(auto-fit,minmax(220px,1fr));gap:18px;margin-top:8px}
+  .step{background:var(--card);border:1px solid var(--line);border-radius:16px;padding:22px 20px;box-shadow:0 10px 30px -20px rgba(18,36,63,.3)}
+  .step .n{font-size:.78rem;font-weight:800;color:var(--accent);letter-spacing:.08em}
+  .step h4{margin:6px 0 6px;font-size:1.04rem}
+  .step p{margin:0;color:var(--muted);font-size:.93rem}
+
+  /* ---------- SET-PRICE PANEL ---------- */
+  .setpanel{
+    margin-top:34px;border:1px solid var(--line);border-radius:22px;
+    background:linear-gradient(160deg,#ffffff,#eef4ea);
+    padding:34px 32px;box-shadow:var(--shadow);position:relative;overflow:hidden;
+  }
+  .setpanel::before{content:"";position:absolute;top:0;left:0;right:0;height:4px;background:linear-gradient(90deg,var(--blue),var(--accent))}
+  .setpanel > .ttl{display:flex;align-items:center;gap:12px;margin-bottom:6px}
+  .setpanel > .ttl .badge{font-size:1.4rem}
+  .setpanel h3{margin:0;font-size:1.35rem;font-weight:800;color:var(--blue)}
+  .setpanel > p{margin:8px 0 0;color:var(--muted);max-width:720px}
+  .setgrid{display:grid;grid-template-columns:repeat(auto-fit,minmax(260px,1fr));gap:20px;margin-top:26px}
+  .setvar{background:#fff;border:1px solid var(--line);border-radius:16px;padding:24px 22px;box-shadow:0 12px 32px -22px rgba(18,36,63,.4);display:flex;flex-direction:column}
+  .setvar .num{
+    width:36px;height:36px;border-radius:11px;display:grid;place-items:center;
+    background:linear-gradient(150deg,var(--blue),var(--blue-2));color:#fff;font-weight:800;
+    font-size:1.05rem;margin-bottom:14px;
+  }
+  .setvar h4{margin:0 0 8px;font-size:1.06rem;line-height:1.3}
+  .setvar h4 small{display:block;font-size:.76rem;font-weight:600;color:var(--accent);letter-spacing:.04em;margin-top:3px}
+  .setvar p{margin:0 0 12px;color:var(--muted);font-size:.93rem}
+  .setvar .kv{margin-top:auto;font-size:.82rem;color:var(--blue);font-weight:600}
+  .pill{display:inline-block;font-size:.72rem;font-weight:700;padding:3px 10px;border-radius:100px;margin-top:10px}
+  .pill.rev{color:#8a6d3b;background:rgba(210,150,40,.14);border:1px solid rgba(210,150,40,.35)}
+  .pill.one{color:#a03d2e;background:rgba(196,69,59,.12);border:1px solid rgba(196,69,59,.3)}
+  .setnote{
+    margin-top:24px;padding:16px 20px;border-radius:14px;
+    background:rgba(27,67,121,.06);border:1px solid rgba(27,67,121,.16);
+    color:#2a3b52;font-size:.92rem;
+  }
+  .setnote b{color:var(--blue)}
+
+  /* ---------- FOOTER ---------- */
+  footer{padding:44px 0;text-align:center;color:var(--muted);font-size:.9rem;border-top:1px solid var(--line)}
+  footer b{color:var(--ink)}
+
+  @media(max-width:760px){
+    .spot{grid-template-columns:1fr}
+    section{padding:48px 0}
+  }
+</style>
+</head>
+<body>
+
+<header class="hero">
+  <div class="wrap">
+    <span class="eyebrow"><span class="dot"></span>Release-Übersicht · 2026</span>
+    <h1>Ihr Intranet wird<br><span class="grad">schneller, sicherer, transparenter.</span></h1>
+    <p class="lede">Die neue Generation des Fuchs Intranets bringt Live-Vorschau bei der Rechnungserstellung, Echtzeit-Rückmeldungen, extern validierte E-Rechnung (ZUGFeRD/DATEV und XRechnung) und eine durchgängig geprüfte Datenverarbeitung — ohne dass sich Ihr gewohnter Arbeitsablauf verändert.</p>
+    <div class="hero-meta">
+      <div><b>E-Rechnung</b><span>ZUGFeRD / XRechnung · extern validiert</span></div>
+      <div><b>Echtzeit</b><span>Live-Vorschau &amp; Benachrichtigungen</span></div>
+      <div><b>.NET 10</b><span>Moderne, geprüfte Plattform</span></div>
+    </div>
+  </div>
+</header>
+
+<!-- WAS NEU IST -->
+<section>
+  <div class="wrap">
+    <div class="section-head">
+      <span class="kicker">Das Wichtigste auf einen Blick</span>
+      <h2>Die neuen Funktionen für Ihren Alltag</h2>
+      <p>Alle Neuerungen zielen auf dasselbe Ziel: weniger Fehler, mehr Überblick und Rechnungen, die auf Anhieb korrekt sind.</p>
+    </div>
+    <div class="grid">
+
+      <div class="card">
+        <div class="ico">👁️</div>
+        <h3>Live-Vorschau beim Bearbeiten</h3>
+        <p>Während Sie eine Rechnung bearbeiten, sehen Sie das fertige PDF sofort in Echtzeit — genau so, wie es der Kunde erhält. Kein Zwischenspeichern, kein Raten mehr.</p>
+        <span class="tag">Rechnungen &amp; Zahlungserinnerungen</span>
+      </div>
+
+      <div class="card">
+        <div class="ico">🧮</div>
+        <h3>Alle Beträge serverseitig berechnet</h3>
+        <p>Summen, Mehrwertsteuer, §13b-Umkehr und offene Beträge rechnet ab sofort der Server — geprüft und einheitlich. Der Bildschirm zeigt immer denselben Stand wie das PDF.</p>
+        <span class="tag">Keine Rechenfehler mehr</span>
+      </div>
+
+      <div class="card">
+        <div class="ico">🔔</div>
+        <h3>Benachrichtigungen in Echtzeit</h3>
+        <p>„Rechnung R2026-0001 wurde an den Kunden versandt." — Erfolg <em>und</em> Fehler erscheinen sofort als deutlich lesbare Meldung. Kein Nachschauen in Listen mehr.</p>
+        <span class="tag">Sofortiges Feedback</span>
+      </div>
+
+      <div class="card">
+        <div class="ico">🧾</div>
+        <h3>Extern geprüfte E-Rechnung</h3>
+        <p>Rechnungen werden automatisch als ZUGFeRD 2.4 / Factur-X (DATEV) ausgegeben — oder, sobald eine Leitweg-ID hinterlegt ist, als XRechnung 3.0 für den Behördenversand. Beide Formate sind bei einem externen Prüfdienst als fehlerfrei (0 Fehler) und PDF/A-3-konform bestätigt.</p>
+        <span class="tag">ZUGFeRD 2.4 · XRechnung 3.0 · Extern validiert</span>
+      </div>
+
+      <div class="card">
+        <div class="ico">🕓</div>
+        <h3>Änderungshistorie &amp; Verwerfen</h3>
+        <p>Jede Änderung an einem Entwurf wird protokolliert. Über „Änderungshistorie" sehen Sie, was passiert ist, und mit „Änderungen verwerfen" kehren Sie jederzeit zum gespeicherten Stand zurück.</p>
+        <span class="tag">Volle Nachvollziehbarkeit</span>
+      </div>
+
+      <div class="card">
+        <div class="ico">🏦</div>
+        <h3>Mehr Bankformate</h3>
+        <p>Kontoauszüge werden jetzt auch im modernen ISO-20022-Format (CAMT) automatisch erkannt und eingelesen — zusätzlich zum bewährten MT940. Das Format wird selbstständig erkannt.</p>
+        <span class="tag">CAMT + MT940</span>
+      </div>
+
+    </div>
+  </div>
+</section>
+
+<!-- SPOTLIGHT: Live-Editor -->
+<section style="padding-top:12px">
+  <div class="wrap">
+    <div class="spot">
+      <div class="spot-text">
+        <span class="chip">Highlight</span>
+        <h2>Der Rechnungs-Editor, der mitdenkt</h2>
+        <p>Früher rechnete der Browser — heute ist der Server die einzige verbindliche Quelle. Das klingt technisch, bedeutet für Sie aber vor allem: Was Sie sehen, stimmt. Immer.</p>
+        <p>Gilt für <strong>alle Rechnungsarten</strong> (Regel-, Abschlags-, Schluss- und Stornorechnung) und <strong>alle Mahnstufen</strong> — das Online-Bild und das PDF sind garantiert identisch, bis hin zur Positionsnummerierung.</p>
+      </div>
+      <div class="spot-card">
+        <h3>Was der Editor jetzt automatisch tut</h3>
+        <ul>
+          <li>Rechnet Netto, MwSt. und Brutto sofort korrekt neu</li>
+          <li>Prüft E-Mail, Adresse, Positionen und Steuersätze live</li>
+          <li>Erzeugt die PDF-Vorschau direkt aus dem aktuellen Stand</li>
+          <li>Nummeriert Positionen auch nach Umsortieren korrekt durch</li>
+          <li>Warnt rechtzeitig, bevor ein Entwurf abläuft</li>
+          <li>Speichert erst final, wenn Sie es bestätigen</li>
+        </ul>
+      </div>
+    </div>
+  </div>
+</section>
+
+<!-- ONLINE-EDITOR IM DETAIL -->
+<section>
+  <div class="wrap">
+    <div class="section-head">
+      <span class="kicker">Der Online-Editor im Detail</span>
+      <h2>Rechnungen direkt im Browser erstellen</h2>
+      <p>Der neue Rechnungs-Editor führt Sie Schritt für Schritt zur fertigen Rechnung — komfortabel zu bedienen und dabei jederzeit rechnerisch abgesichert. Er gilt für alle Rechnungsarten (Regel-, Abschlags-, Schluss- und Stornorechnung).</p>
+    </div>
+
+    <div class="steps">
+      <div class="step"><div class="n">BEARBEITEN</div><h4>Direkt im Feld</h4><p>Texte und Positionen bearbeiten Sie direkt an Ort und Stelle — ein Klick genügt.</p></div>
+      <div class="step"><div class="n">EMPFÄNGER</div><h4>Adresse als Formular</h4><p>Die Rechnungsadresse erfassen Sie strukturiert (Name, Straße, PLZ, Ort, Land, optional USt-IdNr., bei Behörden die Leitweg-ID) — vorausgefüllt aus den Kundendaten, ergänzt um Leistungsdatum bzw. Leistungszeitraum. Ein Hinweis zeigt, ob alles für die DATEV-/E-Rechnung passt; ist eine Leitweg-ID gesetzt, wird automatisch als XRechnung statt ZUGFeRD ausgegeben. Für Privatpersonen bleibt die USt-IdNr. einfach leer.</p></div>
+      <div class="step"><div class="n">ORDNEN</div><h4>Blöcke &amp; Reihenfolge</h4><p>Positionen sind je Auftrag in Abschnitten gebündelt und lassen sich per Ziehen neu sortieren; die Nummerierung passt sich automatisch an.</p></div>
+      <div class="step"><div class="n">RECHNEN</div><h4>Summen &amp; Steuer live</h4><p>Netto, Mehrwertsteuer, Brutto und die §13b-Umkehr werden bei jeder Änderung sofort und geprüft neu berechnet.</p></div>
+      <div class="step"><div class="n">PRÜFEN</div><h4>Vorschau auf Knopfdruck</h4><p>Die PDF-Vorschau entsteht direkt aus dem aktuellen Stand — was Sie sehen, ist exakt das, was der Kunde erhält.</p></div>
+    </div>
+
+    <!-- SET-PREIS-VARIANTEN -->
+    <div class="setpanel">
+      <div class="ttl"><span class="badge">📦</span><h3>Set-Preis: drei Wege, Positionen zusammenzufassen</h3></div>
+      <p>Oft sollen mehrere Einzelpositionen zu <em>einem</em> Set-Preis zusammengefasst werden — etwa als Pauschale pro Auftrag. Dafür gibt es drei klar getrennte Funktionen. Bei allen bleibt die <strong>Rechnungssumme unverändert</strong>; die Set-Zeile trägt genau den Wert der zusammengefassten Positionen.</p>
+
+      <div class="setgrid">
+
+        <div class="setvar">
+          <div class="num">1</div>
+          <h4>Einzelne Set-Position zusammenfassen<small>Zeilen-Schaltfläche · direkt an der Position</small></h4>
+          <p>Für eine einzelne Set-Position: Der Set-Kopf übernimmt die Summe seiner zugehörigen Teilpositionen, deren Einzelpreise werden dann leer dargestellt (kein Preis, nicht 0,00 €).</p>
+          <span class="kv">Wirkt auf: eine markierte Set-Position</span>
+          <span class="pill one">Einmalig — nicht per Klick umkehrbar</span>
+        </div>
+
+        <div class="setvar">
+          <div class="num">2</div>
+          <h4>„Set mit Preis"<small>Menü · ganzer Auftragsblock</small></h4>
+          <p>Für jeden Auftragsblock wird oben eine hervorgehobene Set-Zeile mit dem Gesamtwert des Blocks eingefügt. Die bisherigen Einzelpositionen <strong>bleiben sichtbar</strong>, jedoch ohne Einzelpreis (leeres Preisfeld). Die eingefügte Set-Zeile ist eine echte, nachträglich editierbare Position.</p>
+          <span class="kv">Wirkt auf: jeden Auftragsblock · Positionen bleiben erhalten</span>
+          <span class="pill rev">Einmalige Umwandlung</span>
+        </div>
+
+        <div class="setvar">
+          <div class="num">3</div>
+          <h4>„Nur Set mit Preis"<small>Menü · ganzer Auftragsblock</small></h4>
+          <p>Wie „Set mit Preis" — aber die Einzelpositionen werden <strong>vollständig entfernt</strong>. Es bleibt allein die eine Set-Zeile mit dem Gesamtpreis des Blocks stehen. Ideal für eine schlanke Pauschal-Darstellung.</p>
+          <span class="kv">Wirkt auf: jeden Auftragsblock · Positionen werden entfernt</span>
+          <span class="pill rev">Einmalige Umwandlung</span>
+        </div>
+
+      </div>
+
+      <div class="setnote">
+        <b>Gut zu wissen:</b> Die beiden Menü-Varianten (2 &amp; 3) sind bewusste, <b>einmalige Umwandlungen</b> — es gibt keinen Umschalter zurück. Möchten Sie den Ausgangszustand wiederherstellen, verwerfen Sie einfach den Entwurf („Änderungen verwerfen"), oder passen Sie die entstandene Set-Zeile von Hand an. In jedem Fall gilt: die <b>Gesamtsumme ändert sich nicht</b>, und die PDF-Ausgabe zeigt exakt dasselbe wie der Online-Editor.
+      </div>
+    </div>
+  </div>
+</section>
+
+<!-- BEFORE / AFTER -->
+<section class="compare">
+  <div class="wrap">
+    <div class="section-head">
+      <span class="kicker">Alt gegen Neu</span>
+      <h2>Was sich konkret verbessert hat</h2>
+      <p>Ein direkter Vergleich der bisherigen Lösung mit der neuen Implementierung.</p>
+    </div>
+    <div class="table-scroll">
+      <table>
+        <thead>
+          <tr><th>Bereich</th><th>Bisher (Legacy)</th><th>Neu</th></tr>
+        </thead>
+        <tbody>
+          <tr>
+            <td class="feat">Rechnungs­vorschau</td>
+            <td class="old">Kein Live-PDF — Ergebnis erst nach dem Speichern sichtbar</td>
+            <td class="new">Echtzeit-PDF-Vorschau schon während der Bearbeitung</td>
+          </tr>
+          <tr>
+            <td class="feat">Berechnung</td>
+            <td class="old">Beträge im Browser gerechnet — Abweichungen möglich</td>
+            <td class="new">Alle Werte serverseitig geprüft &amp; einheitlich berechnet</td>
+          </tr>
+          <tr>
+            <td class="feat">Rückmeldungen</td>
+            <td class="old">Keine aktive Meldung — Status nur durch Nachschauen</td>
+            <td class="new">Sofortige Erfolgs- und Fehlermeldungen in Echtzeit</td>
+          </tr>
+          <tr>
+            <td class="feat">Fehler im Hintergrund</td>
+            <td class="old">Nur im Protokoll — für den Nutzer unsichtbar</td>
+            <td class="new">Werden dem Nutzer verständlich angezeigt</td>
+          </tr>
+          <tr>
+            <td class="feat">Rechnungsformat</td>
+            <td class="old">Reines PDF</td>
+            <td class="new">Zusätzlich extern validierte E-Rechnung (ZUGFeRD/DATEV oder XRechnung für Behörden) — 0 Fehler, PDF/A-3 bestätigt</td>
+          </tr>
+          <tr>
+            <td class="feat">Änderungsverlauf</td>
+            <td class="old">Nicht vorhanden</td>
+            <td class="new">Vollständige Historie &amp; gezieltes Verwerfen je Entwurf</td>
+          </tr>
+          <tr>
+            <td class="feat">Kontoauszüge</td>
+            <td class="old">Nur MT940</td>
+            <td class="new">MT940 <em>und</em> CAMT (ISO 20022) mit Auto-Erkennung</td>
+          </tr>
+          <tr>
+            <td class="feat">System-Überblick</td>
+            <td class="old">Kein Einblick in den Systemzustand</td>
+            <td class="new">Admin-/Status-Modul mit Live-Prüfungen (für berechtigte Nutzer)</td>
+          </tr>
+          <tr>
+            <td class="feat">Plattform</td>
+            <td class="old">Ältere VB-Codebasis</td>
+            <td class="new">Modernes .NET 10 — schneller, gepflegt, umfangreich getestet</td>
+          </tr>
+        </tbody>
+      </table>
+    </div>
+  </div>
+</section>
+
+<!-- KEY USER -->
+<section class="keyuser">
+  <div class="wrap">
+    <div class="section-head">
+      <span class="kicker" style="color:var(--accent-2)">Für den Key-User</span>
+      <h2>Mehr Kontrolle hinter den Kulissen</h2>
+      <p>Diese Punkte betreffen vor allem Sie als Key-User — sie sorgen dafür, dass der Betrieb stabil, nachvollziehbar und überprüfbar bleibt.</p>
+    </div>
+    <div class="ku-grid">
+      <div class="ku">
+        <h3><span>◆</span> Admin- &amp; Status-Modul</h3>
+        <p>Ein eigenes Modul zeigt den Zustand des Systems: Server, Datenbank, Schlüsseltresor, Speicher und die ERP-Anbindung werden live geprüft. Inklusive Test-E-Mail-Funktion — sichtbar nur für berechtigte Nutzer.</p>
+      </div>
+      <div class="ku">
+        <h3><span>◆</span> Durchgängige Nachvollziehbarkeit</h3>
+        <p>Jeder wichtige Geschäftsvorfall — erstellt, versandt, importiert, fehlgeschlagen — wird als Ereignis erfasst und in verständliche Meldungen übersetzt.</p>
+      </div>
+      <div class="ku">
+        <h3><span>◆</span> Überwachung &amp; Diagnose</h3>
+        <p>Moderne Telemetrie (OpenTelemetry) misst Abläufe, Laufzeiten und Fehler. Probleme lassen sich damit früher erkennen und schneller eingrenzen.</p>
+      </div>
+      <div class="ku">
+        <h3><span>◆</span> Automatischer ERP-Abgleich</h3>
+        <p>Der Abgleich mit dem ERP-System (mfr) läuft zuverlässig im Hintergrund direkt in der Anwendung — mit automatischer Wiederholung bei kurzzeitigen Störungen.</p>
+      </div>
+      <div class="ku">
+        <h3><span>◆</span> Sichere Konfiguration</h3>
+        <p>Zugangsdaten liegen im zentralen Azure Key Vault. Eine Test-Schutzfunktion verhindert, dass in Test-Umgebungen versehentlich echte Kunden angeschrieben werden.</p>
+      </div>
+      <div class="ku">
+        <h3><span>◆</span> Umfassend getestet</h3>
+        <p>Die Kernlogik ist durch eine breite, automatisierte Testabdeckung abgesichert — erfolgreiche wie fehlerhafte Abläufe werden geprüft, bevor Änderungen live gehen.</p>
+      </div>
+    </div>
+  </div>
+</section>
+
+<!-- UNVERÄNDERT / VERTRAUT -->
+<section>
+  <div class="wrap">
+    <div class="section-head">
+      <span class="kicker">Vertraut geblieben</span>
+      <h2>Was sich für Sie <em>nicht</em> ändert</h2>
+      <p>Modernisiert wurde die Technik — nicht Ihre Arbeitsweise.</p>
+    </div>
+    <div class="grid">
+      <div class="card"><div class="ico">🗂️</div><h3>Gewohnte Module</h3><p>Rechnungen, Zahlungserinnerungen, Anfragen, Banking und Berichte finden Sie an denselben Stellen wie bisher.</p></div>
+      <div class="card"><div class="ico">📄</div><h3>Vertrautes Layout</h3><p>Briefkopf, Adressfenster und Rechnungslayout wurden 1:1 übernommen — Ihre Dokumente sehen aus wie gewohnt.</p></div>
+      <div class="card"><div class="ico">🔐</div><h3>Gleiche Anmeldung</h3><p>Login und Berechtigungen bleiben unverändert. Neue Funktionen erscheinen nur dort, wo Sie dafür berechtigt sind.</p></div>
+    </div>
+  </div>
+</section>
+
+<footer>
+  <div class="wrap">
+    <p><b>Fuchs Intranet</b> — Neue Implementierung · Stand Juli 2026<br>
+    Sebastian Fuchs Bad und Heizung GmbH &amp; Co. KG · Bereitgestellt von ProcessWeb</p>
+  </div>
+</footer>
+
+</body>
+</html>

Fuchs/Docs/Notes/ToDo.md

@@ -0,0 +1,12 @@
+
+The items, if completed, should be ticked / checked as done.
+
+[x] Add note to `claude.md`, `copilot-instructions.md`, and `Codex.md` that the Decisions ind \Docs\Decisions  must be followed
+[x] Add note to `claude.md`, `copilot-instructions.md`, and `Codex.md` that whenever relevant new decisions should be captured, concept files should be created / updated
+[x] Add note to `claude.md`, `copilot-instructions.md`, and `Codex.md` that the readme.md files in \Docs\Concept and \Docs\Decisions explain how to create, update, interpret the documents.  Create those readme.md files. make sure that any concepts or decisions have a yaml header that contains applyTo key. The agents should scan those yaml headers first (saving tokens) and decide based on that if included/considered
+[x] Add a first decision, that domain events (success and fails) should be identified and equiped with triggers that trigger notification to the EventService and pass on a context that allows a user understandable message like "Rechnung R2026-0001 wurde and Kunden unter test@test.de per Email versandt".
+[x] Add a decision that reflects the current concept and implementation of Notification from Service in Backend over SignalR push to any logged in session to display in GUI. (failues with highlighting)
+[x] Add a decision that the solution must be equiped with logging so that the diagnostics is possible without requiring a debugger or OTel collector.
+[x] Add OpenTelemetry to the solution. Wire it in extensively without compromising performance.
+[x] Add note to `claude.md`, `copilot-instructions.md`, and `Codex.md` that the unit tests should be as extensive as possible and cover false positive also. (could be imlcuded already
+

Fuchs/Fuchs.csproj

@@ -22,9 +22,9 @@
     <ProjectReference Include="..\OCORE_web\OCORE_web\OCORE_web.csproj" />
     <ProjectReference Include="..\OCORE_web_pdf\OCORE_web_pdf.csproj" />
     <ProjectReference Include="..\CAMTParser\CAMTParser.csproj" />
+    <ProjectReference Include="..\eRechnungLib\src\eRechnungLib\eRechnungLib.csproj" />
   </ItemGroup>
   <ItemGroup>
-    <Content Include="code\7z.dll" CopyToOutputDirectory="PreserveNewest" />
     <Content Include="Data\**" CopyToOutputDirectory="PreserveNewest" />
     <Content Include="favicon.ico" />
   </ItemGroup>
@@ -34,18 +34,17 @@
     <PackageReference Include="HtmlAgilityPack" Version="1.12.4" />
     <PackageReference Include="MailKit" Version="4.17.0" />
     <PackageReference Include="Microsoft.IO.RecyclableMemoryStream" Version="3.0.1" />
-    <PackageReference Include="OpenTelemetry.Exporter.OpenTelemetryProtocol" Version="1.16.0" />
-    <PackageReference Include="OpenTelemetry.Extensions.Hosting" Version="1.16.0" />
+    <PackageReference Include="OpenTelemetry.Exporter.OpenTelemetryProtocol" Version="1.17.0" />
+    <PackageReference Include="OpenTelemetry.Extensions.Hosting" Version="1.17.0" />
     <PackageReference Include="OpenTelemetry.Instrumentation.AspNetCore" Version="1.16.0" />
     <PackageReference Include="OpenTelemetry.Instrumentation.Http" Version="1.16.0" />
-    <PackageReference Include="OpenTelemetry.Instrumentation.Runtime" Version="1.15.1" />
+    <PackageReference Include="OpenTelemetry.Instrumentation.Runtime" Version="1.16.0" />
     <PackageReference Include="OpenTelemetry.Instrumentation.SqlClient" Version="1.16.0" />
     <PackageReference Include="Portable.BouncyCastle" Version="1.9.0" />
     <PackageReference Include="QRCoder" Version="1.8.0" />
 	  <PackageReference Include="PDFsharp" Version="6.2.4" />
 	  <PackageReference Include="PDFsharp-MigraDoc" Version="6.2.4" />
 	  <PackageReference Include="Spire.PDF" Version="[8.10.5,8.10.5]" allowedVersions="[8.10.5,8.10.5]" />
-    <PackageReference Include="Squid-Box.SevenZipSharp" Version="1.6.2.24" />
     <!-- Updated packages -->
     <PackageReference Include="BouncyCastle.Cryptography" Version="2.6.2" />
     <PackageReference Include="MimeKit" Version="4.17.0" />
@@ -53,8 +52,8 @@
     <!-- New packages (needed for .NET 10) -->
     <PackageReference Include="Microsoft.Data.SqlClient" Version="7.0.2" />
     <PackageReference Include="SixLabors.ImageSharp" Version="4.0.0" />
-    <PackageReference Include="System.Configuration.ConfigurationManager" Version="10.0.9" />
-    <PackageReference Include="System.Drawing.Common" Version="10.0.9" />
+    <PackageReference Include="System.Configuration.ConfigurationManager" Version="10.0.10" />
+    <PackageReference Include="System.Drawing.Common" Version="10.0.10" />
     <PackageReference Include="Azure.Storage.Blobs" Version="12.29.1" />
   </ItemGroup>
   <ItemGroup>
@@ -66,14 +65,12 @@
 
 
 	<!-- UsingTask für plattformneutrales Zippen nach Publish -->
-	<UsingTask TaskName="ZipDir" TaskFactory="CodeTaskFactory" AssemblyName="Microsoft.Build.Tasks.Core">
+	<UsingTask TaskName="ZipDir" TaskFactory="RoslynCodeTaskFactory" AssemblyName="Microsoft.Build.Tasks.Core">
 		<ParameterGroup>
 			<Source ParameterType="System.String" Required="true" />
 			<Destination ParameterType="System.String" Required="true" />
 		</ParameterGroup>
 		<Task>
-			<Reference Include="System.IO.Compression" />
-			<Reference Include="System.IO.Compression.FileSystem" />
 			<Code Type="Fragment" Language="cs">
 				<![CDATA[
         if (System.IO.File.Exists(Destination)) {

Fuchs/Notifications/DomainEvent.cs

@@ -0,0 +1,36 @@
+namespace Fuchs.Notifications;
+
+public enum DomainEventType
+{
+    InvoiceDraftCreated,
+    InvoiceDraftUpdated,
+    InvoiceFileCreated,
+    InvoiceSentToCustomer,
+    InvoiceResentToCustomer,
+    InvoiceMarkedSent,
+    InvoiceCreationFailed,
+    InvoiceFileCreationFailed,
+    InvoiceSendFailed,
+    ReminderDraftCreated,
+    ReminderDraftUpdated,
+    ReminderFileCreated,
+    ReminderSentToCustomer,
+    ReminderResentToCustomer,
+    ReminderMarkedSent,
+    ReminderCreationFailed,
+    ReminderFileCreationFailed,
+    ReminderSendFailed,
+    BankingTransactionsImported,
+    BankingImportFailed,
+    BankingTransactionMarkedDone,
+    UserIssue
+}
+
+public sealed record DomainEvent(
+    DomainEventType Type,
+    string UserAccountId,
+    string Title,
+    IReadOnlyDictionary<string, object?> Context)
+{
+    public DateTimeOffset CreatedAt { get; init; } = DateTimeOffset.UtcNow;
+}

Fuchs/Notifications/DraftNotifier.cs

@@ -0,0 +1,45 @@
+using Microsoft.AspNetCore.SignalR;
+using Microsoft.Extensions.Logging;
+
+namespace Fuchs.Notifications;
+
+/// <summary>
+/// <see cref="IDraftNotifier"/> over the <see cref="DraftPreviewHub"/>. Sends to the
+/// SignalR group named after the draft token so only the editing browser is notified.
+/// Like <see cref="EventService.PublishAsync"/>, delivery failures are logged and
+/// swallowed — a missed coordination ping must never fail the underlying operation
+/// (the client also re-syncs on reconnect and on its next POST).
+/// </summary>
+public sealed class DraftNotifier : IDraftNotifier
+{
+    private readonly IHubContext<DraftPreviewHub> _hub;
+    private readonly ILogger<DraftNotifier> _logger;
+
+    public DraftNotifier(IHubContext<DraftPreviewHub> hub, ILogger<DraftNotifier> logger)
+    {
+        _hub = hub;
+        _logger = logger;
+    }
+
+    public Task SignalDraftReadyAsync(string token, int version, CancellationToken cancellationToken = default) =>
+        SendAsync(token, "draftReady", new { token, version }, cancellationToken);
+
+    public Task SignalExpiringAsync(string token, int secondsLeft, CancellationToken cancellationToken = default) =>
+        SendAsync(token, "draftExpiring", new { token, secondsLeft }, cancellationToken);
+
+    public Task SignalClosedAsync(string token, string reason, CancellationToken cancellationToken = default) =>
+        SendAsync(token, "draftClosed", new { token, reason }, cancellationToken);
+
+    private async Task SendAsync(string token, string method, object payload, CancellationToken cancellationToken)
+    {
+        if (string.IsNullOrEmpty(token)) return;
+        try
+        {
+            await _hub.Clients.Group(token).SendAsync(method, payload, cancellationToken);
+        }
+        catch (Exception ex)
+        {
+            _logger.LogWarning(ex, "Draft signal {Method} failed for token {Token}", method, token);
+        }
+    }
+}

Fuchs/Notifications/DraftPreviewHub.cs

@@ -0,0 +1,31 @@
+using Microsoft.AspNetCore.Authorization;
+using Microsoft.AspNetCore.SignalR;
+
+namespace Fuchs.Notifications;
+
+/// <summary>
+/// SignalR hub for live invoice/reminder draft editing (see ADR 0006 / 0007).
+///
+/// Deliberately separate from <see cref="NotificationHub"/>: that hub broadcasts
+/// business toasts to <b>all</b> logged-in sessions (ADR 0002), whereas draft
+/// signals must be <b>targeted</b> at the one browser editing a given draft.
+/// Targeting is done with a SignalR group named after the draft's session token —
+/// each editor calls <see cref="JoinDraft"/> after opening a draft.
+///
+/// The hub carries no commands: edits, saves and discards travel as ordinary POSTs
+/// (see ADR 0006). The hub only manages group membership and delivers the server's
+/// <c>draftReady</c> / <c>draftExpiring</c> / <c>draftClosed</c> signals.
+/// </summary>
+[Authorize]
+public sealed class DraftPreviewHub : Hub
+{
+    /// <summary>Subscribes this connection to a draft's signal group.</summary>
+    public Task JoinDraft(string token) =>
+        string.IsNullOrEmpty(token) ? Task.CompletedTask
+            : Groups.AddToGroupAsync(Context.ConnectionId, token);
+
+    /// <summary>Unsubscribes this connection from a draft's signal group.</summary>
+    public Task LeaveDraft(string token) =>
+        string.IsNullOrEmpty(token) ? Task.CompletedTask
+            : Groups.RemoveFromGroupAsync(Context.ConnectionId, token);
+}

Fuchs/Notifications/EventService.cs

@@ -0,0 +1,321 @@
+using System.Globalization;
+using Fuchs.intranet;
+using Microsoft.AspNetCore.SignalR;
+using Microsoft.Extensions.Logging;
+using static OCORE.OCORE_dictionaries;
+
+namespace Fuchs.Notifications;
+
+public sealed class EventService : IEventService
+{
+    private readonly IHubContext<NotificationHub> _hub;
+    private readonly ILogger<EventService> _logger;
+
+    public EventService(IHubContext<NotificationHub> hub, ILogger<EventService> logger)
+    {
+        _hub = hub;
+        _logger = logger;
+    }
+
+    public async Task PublishAsync(DomainEvent domainEvent, CancellationToken cancellationToken = default)
+    {
+        try
+        {
+            GuiNotification notification = BuildNotification(domainEvent);
+            await _hub.Clients
+                .All
+                .SendAsync("notification", notification, cancellationToken);
+        }
+        catch (Exception ex)
+        {
+            _logger.LogWarning(ex, "Notification publish failed for {EventType}", domainEvent.Type);
+        }
+    }
+
+    public Task InvoiceDraftRegisteredAsync(FdsInvoiceData invoice, bool changed, string userAccountId)
+    {
+        var type = changed ? DomainEventType.InvoiceDraftUpdated : DomainEventType.InvoiceDraftCreated;
+        return PublishAsync(new DomainEvent(type, userAccountId, "Rechnungsentwurf", InvoiceContext(invoice)));
+    }
+
+    public Task InvoiceFileCreatedAsync(FdsInvoiceData invoice, string fileName, string userAccountId)
+    {
+        var ctx = InvoiceContext(invoice);
+        ctx["fileName"] = fileName;
+        return PublishAsync(new DomainEvent(DomainEventType.InvoiceFileCreated, userAccountId, "Rechnungsdatei", ctx));
+    }
+
+    public Task InvoiceSentToCustomerAsync(FdsInvoiceData invoice, string email, string userAccountId, bool resent = false)
+    {
+        var ctx = InvoiceContext(invoice);
+        ctx["email"] = email;
+        return PublishAsync(new DomainEvent(
+            resent ? DomainEventType.InvoiceResentToCustomer : DomainEventType.InvoiceSentToCustomer,
+            userAccountId,
+            "Rechnung versandt",
+            ctx));
+    }
+
+    public Task InvoiceMarkedSentAsync(string invoiceId, string invoiceNumber, string userAccountId)
+    {
+        Dictionary<string, object?> ctx = new()
+        {
+            ["id"] = invoiceId,
+            ["invoiceNumber"] = string.IsNullOrWhiteSpace(invoiceNumber) ? invoiceId : invoiceNumber
+        };
+        return PublishAsync(new DomainEvent(DomainEventType.InvoiceMarkedSent, userAccountId, "Rechnung markiert", ctx));
+    }
+
+    public Task InvoiceIssueAsync(string message, string userAccountId, string invoiceId = "")
+        => PublishAsync(new DomainEvent(
+            DomainEventType.InvoiceCreationFailed,
+            userAccountId,
+            "Rechnung",
+            new Dictionary<string, object?> { ["id"] = invoiceId, ["message"] = message }));
+
+    public Task ReminderDraftCreatedAsync(FdsReminderData reminder, string userAccountId)
+        => PublishAsync(new DomainEvent(DomainEventType.ReminderDraftCreated, userAccountId, "Mahnentwurf", ReminderContext(reminder)));
+
+    public Task ReminderDraftRegisteredAsync(FdsReminderData reminder, bool changed, string userAccountId)
+    {
+        var type = changed ? DomainEventType.ReminderDraftUpdated : DomainEventType.ReminderDraftCreated;
+        return PublishAsync(new DomainEvent(type, userAccountId, "Mahnentwurf", ReminderContext(reminder)));
+    }
+
+    public Task ReminderFileCreatedAsync(FdsReminderData reminder, string fileName, string userAccountId)
+    {
+        var ctx = ReminderContext(reminder);
+        ctx["fileName"] = fileName;
+        return PublishAsync(new DomainEvent(DomainEventType.ReminderFileCreated, userAccountId, "Mahndatei", ctx));
+    }
+
+    public Task ReminderSentToCustomerAsync(FdsReminderData reminder, string email, string userAccountId, bool resent = false)
+    {
+        var ctx = ReminderContext(reminder);
+        ctx["email"] = email;
+        return PublishAsync(new DomainEvent(
+            resent ? DomainEventType.ReminderResentToCustomer : DomainEventType.ReminderSentToCustomer,
+            userAccountId,
+            "Mahnung versandt",
+            ctx));
+    }
+
+    public Task ReminderMarkedSentAsync(string reminderId, string reminderTitle, string userAccountId)
+    {
+        Dictionary<string, object?> ctx = new()
+        {
+            ["id"] = reminderId,
+            ["title"] = string.IsNullOrWhiteSpace(reminderTitle) ? reminderId : reminderTitle
+        };
+        return PublishAsync(new DomainEvent(DomainEventType.ReminderMarkedSent, userAccountId, "Mahnung markiert", ctx));
+    }
+
+    public Task ReminderIssueAsync(string message, string userAccountId, string reminderId = "")
+        => PublishAsync(new DomainEvent(
+            DomainEventType.ReminderCreationFailed,
+            userAccountId,
+            "Mahnung",
+            new Dictionary<string, object?> { ["id"] = reminderId, ["message"] = message }));
+
+    public Task BankingTransactionsImportedAsync(DateTime? from, DateTime? to, int rows, string fileName, string userAccountId)
+        => PublishAsync(new DomainEvent(
+            DomainEventType.BankingTransactionsImported,
+            userAccountId,
+            "Banking",
+            new Dictionary<string, object?>
+            {
+                ["from"] = from,
+                ["to"] = to,
+                ["rows"] = rows,
+                ["fileName"] = fileName
+            }));
+
+    public Task BankingImportIssueAsync(string message, string fileName, string userAccountId)
+        => PublishAsync(new DomainEvent(
+            DomainEventType.BankingImportFailed,
+            userAccountId,
+            "Banking",
+            new Dictionary<string, object?> { ["fileName"] = fileName, ["message"] = message }));
+
+    public Task BankingTransactionMarkedDoneAsync(string taId, DateTime? valueDate, decimal? amount, string userAccountId)
+        => PublishAsync(new DomainEvent(
+            DomainEventType.BankingTransactionMarkedDone,
+            userAccountId,
+            "Banking",
+            new Dictionary<string, object?>
+            {
+                ["taId"] = taId,
+                ["valueDate"] = valueDate,
+                ["amount"] = amount
+            }));
+
+    public Task UserIssueAsync(string title, string message, string userAccountId, IReadOnlyDictionary<string, object?>? context = null)
+    {
+        Dictionary<string, object?> ctx = context == null
+            ? new Dictionary<string, object?>()
+            : new Dictionary<string, object?>(context);
+        ctx["message"] = message;
+        return PublishAsync(new DomainEvent(DomainEventType.UserIssue, userAccountId, title, ctx));
+    }
+
+    private static GuiNotification BuildNotification(DomainEvent domainEvent)
+    {
+        string message = domainEvent.Type switch
+        {
+            DomainEventType.InvoiceDraftCreated =>
+                $"Rechnungsentwurf {Ctx(domainEvent, "invoiceNumber")} wurde erstellt.",
+            DomainEventType.InvoiceDraftUpdated =>
+                $"Rechnungsentwurf {Ctx(domainEvent, "invoiceNumber")} wurde aktualisiert.",
+            DomainEventType.InvoiceFileCreated =>
+                $"Rechnungsdatei {Ctx(domainEvent, "fileName")} wurde erstellt.",
+            DomainEventType.InvoiceSentToCustomer =>
+                $"Rechnung {Ctx(domainEvent, "invoiceNumber")} wurde an den Kunden mit der E-Mail {Ctx(domainEvent, "email")} versandt.",
+            DomainEventType.InvoiceResentToCustomer =>
+                $"Rechnung {Ctx(domainEvent, "invoiceNumber")} wurde erneut an {Ctx(domainEvent, "email")} versandt.",
+            DomainEventType.InvoiceMarkedSent =>
+                $"Rechnung {Ctx(domainEvent, "invoiceNumber")} wurde als versandt markiert.",
+            DomainEventType.InvoiceCreationFailed =>
+                Ctx(domainEvent, "message"),
+            DomainEventType.InvoiceFileCreationFailed =>
+                Ctx(domainEvent, "message"),
+            DomainEventType.InvoiceSendFailed =>
+                Ctx(domainEvent, "message"),
+            DomainEventType.ReminderDraftCreated =>
+                $"Mahnentwurf {Ctx(domainEvent, "title")} wurde erstellt.",
+            DomainEventType.ReminderDraftUpdated =>
+                $"Mahnentwurf {Ctx(domainEvent, "title")} wurde aktualisiert.",
+            DomainEventType.ReminderFileCreated =>
+                $"Mahndatei {Ctx(domainEvent, "fileName")} wurde erstellt.",
+            DomainEventType.ReminderSentToCustomer =>
+                $"Mahnung {Ctx(domainEvent, "title")} wurde an den Kunden mit der E-Mail {Ctx(domainEvent, "email")} versandt.",
+            DomainEventType.ReminderResentToCustomer =>
+                $"Mahnung {Ctx(domainEvent, "title")} wurde erneut an {Ctx(domainEvent, "email")} versandt.",
+            DomainEventType.ReminderMarkedSent =>
+                $"Mahnung {Ctx(domainEvent, "title")} wurde als versandt markiert.",
+            DomainEventType.ReminderCreationFailed =>
+                Ctx(domainEvent, "message"),
+            DomainEventType.ReminderFileCreationFailed =>
+                Ctx(domainEvent, "message"),
+            DomainEventType.ReminderSendFailed =>
+                Ctx(domainEvent, "message"),
+            DomainEventType.BankingTransactionsImported =>
+                BankingImportMessage(domainEvent),
+            DomainEventType.BankingImportFailed =>
+                Ctx(domainEvent, "message"),
+            DomainEventType.BankingTransactionMarkedDone =>
+                BankingTransactionMarkedDoneMessage(domainEvent),
+            DomainEventType.UserIssue =>
+                Ctx(domainEvent, "message"),
+            _ => domainEvent.Title
+        };
+
+        return new GuiNotification(
+            Guid.NewGuid().ToString("N"),
+            domainEvent.Type.ToString(),
+            domainEvent.Title,
+            message,
+            IsFailure(domainEvent.Type) ? "error" : "info",
+            domainEvent.CreatedAt,
+            domainEvent.Context);
+    }
+
+    private static bool IsFailure(DomainEventType type) =>
+        type is DomainEventType.InvoiceCreationFailed
+            or DomainEventType.InvoiceFileCreationFailed
+            or DomainEventType.InvoiceSendFailed
+            or DomainEventType.ReminderCreationFailed
+            or DomainEventType.ReminderFileCreationFailed
+            or DomainEventType.ReminderSendFailed
+            or DomainEventType.BankingImportFailed
+            or DomainEventType.UserIssue;
+
+    private static string BankingImportMessage(DomainEvent domainEvent)
+    {
+        int rows = int.TryParse(Ctx(domainEvent, "rows"), out int r) ? r : 0;
+        string movement = rows == 1 ? "Kontobewegung" : "Kontobewegungen";
+        string period = BankingPeriod(domainEvent);
+        return string.IsNullOrEmpty(period)
+            ? $"{rows} {movement} wurden importiert."
+            : $"{movement} für {period} wurden importiert.";
+    }
+
+    private static string BankingPeriod(DomainEvent domainEvent)
+    {
+        DateTime? from = DateCtx(domainEvent, "from");
+        DateTime? to = DateCtx(domainEvent, "to");
+        if (from == null && to == null) return "";
+        if (from != null && to != null)
+        {
+            string fromFmt = from.Value.Year == to.Value.Year
+                ? from.Value.ToString("d.M.")
+                : from.Value.ToString("d.M.yyyy");
+            string toFmt = from.Value.Year == to.Value.Year
+                ? to.Value.ToString("dd.MM.")
+                : to.Value.ToString("dd.MM.yyyy");
+            return $"{fromFmt} - {toFmt}";
+        }
+        return (from ?? to)!.Value.ToString("dd.MM.yyyy");
+    }
+
+    private static DateTime? DateCtx(DomainEvent domainEvent, string key)
+    {
+        if (!domainEvent.Context.TryGetValue(key, out var value) || value == null) return null;
+        if (value is DateTime dt) return dt;
+        if (value is DateTimeOffset dto) return dto.DateTime;
+        return DateTime.TryParse(value.ToString(), out var parsed) ? parsed : null;
+    }
+
+    private static string BankingTransactionMarkedDoneMessage(DomainEvent domainEvent)
+    {
+        DateTime? valueDate = DateCtx(domainEvent, "valueDate");
+        string amount = AmountCtx(domainEvent, "amount");
+        string datePart = valueDate == null ? "" : $" vom {valueDate.Value:dd.MM.yy}";
+        string amountPart = string.IsNullOrEmpty(amount) ? "" : $" über {amount}€";
+        return $"Bank-Transaktion{datePart}{amountPart} wurde als erledigt markiert.";
+    }
+
+    private static string AmountCtx(DomainEvent domainEvent, string key)
+    {
+        if (!domainEvent.Context.TryGetValue(key, out var value) || value == null) return "";
+        decimal? amount = value switch
+        {
+            decimal d => d,
+            double d => (decimal)d,
+            _ => decimal.TryParse(value.ToString(), NumberStyles.Any, CultureInfo.InvariantCulture, out var parsed)
+                ? parsed
+                : null
+        };
+        return amount?.ToString("0.00", Fuchs_intranet.DeCulture) ?? "";
+    }
+
+    private static Dictionary<string, object?> InvoiceContext(FdsInvoiceData invoice)
+    {
+        string invoiceNumber = invoice.InvoiceId;
+        return new Dictionary<string, object?>
+        {
+            ["id"] = invoice.Id,
+            ["invoiceNumber"] = string.IsNullOrWhiteSpace(invoiceNumber) ? invoice.Id : invoiceNumber,
+            ["documentName"] = invoice.InvoiceRegistration?.getString("DocumentName") ?? "",
+            ["email"] = invoice.InvoiceRegistration?.getString("SendToEmail") ?? "",
+            ["title"] = invoice.InvoiceTitle
+        };
+    }
+
+    private static Dictionary<string, object?> ReminderContext(FdsReminderData reminder)
+    {
+        return new Dictionary<string, object?>
+        {
+            ["id"] = reminder.Id,
+            ["invoiceNumber"] = reminder.InvoiceId,
+            ["title"] = string.IsNullOrWhiteSpace(reminder.ReminderTitle) ? reminder.Id : reminder.ReminderTitle,
+            ["documentName"] = reminder.ReminderRegistration?.getString("DocumentName") ?? "",
+            ["email"] = reminder.InvoiceEmail
+        };
+    }
+
+    private static string Ctx(DomainEvent domainEvent, string key)
+    {
+        if (!domainEvent.Context.TryGetValue(key, out var value)) return "";
+        return value?.ToString() ?? "";
+    }
+}

Fuchs/Notifications/GuiNotification.cs

@@ -0,0 +1,10 @@
+namespace Fuchs.Notifications;
+
+public sealed record GuiNotification(
+    string Id,
+    string Type,
+    string Title,
+    string Message,
+    string Severity,
+    DateTimeOffset CreatedAt,
+    IReadOnlyDictionary<string, object?> Context);

Fuchs/Notifications/IDraftNotifier.cs

@@ -0,0 +1,20 @@
+namespace Fuchs.Notifications;
+
+/// <summary>
+/// Sends <b>system-internal</b> draft-editing signals to the one browser editing a
+/// given draft, over the <see cref="DraftPreviewHub"/> group keyed by session token
+/// (see ADR 0006 / 0007). These are coordination pings, not business notifications:
+/// user-facing success/failure messages (e.g. "Zwischenstand gespeichert") still go
+/// through <see cref="IEventService"/> / <see cref="NotificationHub"/>.
+/// </summary>
+public interface IDraftNotifier
+{
+    /// <summary>The cached draft reached a new <paramref name="version"/> — the client should re-fetch its state.</summary>
+    Task SignalDraftReadyAsync(string token, int version, CancellationToken cancellationToken = default);
+
+    /// <summary>The draft is about to expire in <paramref name="secondsLeft"/>s unless saved — warn the user.</summary>
+    Task SignalExpiringAsync(string token, int secondsLeft, CancellationToken cancellationToken = default);
+
+    /// <summary>The draft session was removed (evicted/expired/discarded) — the client must close the editor and show why.</summary>
+    Task SignalClosedAsync(string token, string reason, CancellationToken cancellationToken = default);
+}

Fuchs/Notifications/IEventService.cs

@@ -0,0 +1,27 @@
+using Fuchs.intranet;
+
+namespace Fuchs.Notifications;
+
+public interface IEventService
+{
+    Task PublishAsync(DomainEvent domainEvent, CancellationToken cancellationToken = default);
+
+    Task InvoiceDraftRegisteredAsync(FdsInvoiceData invoice, bool changed, string userAccountId);
+    Task InvoiceFileCreatedAsync(FdsInvoiceData invoice, string fileName, string userAccountId);
+    Task InvoiceSentToCustomerAsync(FdsInvoiceData invoice, string email, string userAccountId, bool resent = false);
+    Task InvoiceMarkedSentAsync(string invoiceId, string invoiceNumber, string userAccountId);
+    Task InvoiceIssueAsync(string message, string userAccountId, string invoiceId = "");
+
+    Task ReminderDraftCreatedAsync(FdsReminderData reminder, string userAccountId);
+    Task ReminderDraftRegisteredAsync(FdsReminderData reminder, bool changed, string userAccountId);
+    Task ReminderFileCreatedAsync(FdsReminderData reminder, string fileName, string userAccountId);
+    Task ReminderSentToCustomerAsync(FdsReminderData reminder, string email, string userAccountId, bool resent = false);
+    Task ReminderMarkedSentAsync(string reminderId, string reminderTitle, string userAccountId);
+    Task ReminderIssueAsync(string message, string userAccountId, string reminderId = "");
+
+    Task BankingTransactionsImportedAsync(DateTime? from, DateTime? to, int rows, string fileName, string userAccountId);
+    Task BankingImportIssueAsync(string message, string fileName, string userAccountId);
+    Task BankingTransactionMarkedDoneAsync(string taId, DateTime? valueDate, decimal? amount, string userAccountId);
+
+    Task UserIssueAsync(string title, string message, string userAccountId, IReadOnlyDictionary<string, object?>? context = null);
+}

Fuchs/Notifications/NotificationHub.cs

@@ -0,0 +1,9 @@
+using Microsoft.AspNetCore.Authorization;
+using Microsoft.AspNetCore.SignalR;
+
+namespace Fuchs.Notifications;
+
+[Authorize]
+public sealed class NotificationHub : Hub
+{
+}

Fuchs/Observability/FuchsTelemetry.cs

@@ -39,12 +39,21 @@ public static class FuchsTelemetry
         Meter.CreateCounter<long>("fuchs.sms.sent", "{sms}", "Number of SMS messages sent.");
     public static readonly Counter<long> Mt940RowsParsed =
         Meter.CreateCounter<long>("fuchs.banking.mt940.rows", "{row}", "Number of MT940 transaction lines parsed.");
+    public static readonly Counter<long> BankingEntriesSkipped =
+        Meter.CreateCounter<long>("fuchs.banking.entries.skipped", "{entry}",
+            "Number of bank statement entries/statements dropped during parsing, tagged by reason.");
+    public static readonly Counter<long> BankingFieldsTruncated =
+        Meter.CreateCounter<long>("fuchs.banking.fields.truncated", "{field}",
+            "Number of parsed fields truncated to fit the destination column width.");
     public static readonly Counter<long> MfrCalls =
         Meter.CreateCounter<long>("fuchs.mfr.calls", "{call}", "Number of MFR ERP client calls initiated.");
     public static readonly Counter<long> BlobUploadsSucceeded =
         Meter.CreateCounter<long>("fuchs.blobstorage.uploads", "{upload}", "Number of documents successfully archived to Azure Blob Storage.");
     public static readonly Counter<long> BlobUploadsFailed =
         Meter.CreateCounter<long>("fuchs.blobstorage.uploads.failed", "{upload}", "Number of documents that failed to archive to Azure Blob Storage.");
+    public static readonly Counter<long> SystemProbes =
+        Meter.CreateCounter<long>("fuchs.systemstatus.probes", "{probe}",
+            "Admin system-status connectivity probes executed, tagged by component and outcome.");
 
     // ── Performance histograms (durations in milliseconds) ───────────────────
     public static readonly Histogram<double> PdfRenderDuration =

Fuchs/Program.cs

@@ -1,5 +1,6 @@
 using Fuchs.intranet;
 using Fuchs.Logging;
+using Fuchs.Notifications;
 using Fuchs.Observability;
 using OCORE_web.Secrets;
 using Fuchs.Services;
@@ -36,6 +37,14 @@ public class Program
         // Key Vault + DPAPI secret management (must run before FuchsOcmsIntranet.Initialize)
         builder.AddSecretManagement();
 
+        // Apply the Spire.PDF license as early as possible — Spire evaluates its license
+        // lazily on the first PDF operation per process and caches the result, so it must be
+        // set before any Spire use (self-test, first render) or the evaluation watermark sticks
+        // for the whole process. Sourced from the SpirePdf-License managed secret (config key
+        // SpirePdf_License, plus tolerated spelling variants); falls back to the embedded key.
+        FuchsPdf.SetLicense(
+            FuchsPdfService.ResolveLicenseFromConfiguration(builder.Configuration, out _));
+
         // Assemble connection strings from templates + resolved credentials.
         // In Development, "_Dev"-suffixed credential keys are preferred so a reachable
         // Key Vault can never override them with production DB credentials.
@@ -50,8 +59,34 @@ public class Program
         // FDS MFR singleton — ILogger<FdsMfr> and ILoggerFactory are supplied by the ASP.NET Core DI container
         builder.Services.AddSingleton<fds.IFdsMfr, fds.FdsMfr>();
 
+        // In-process MFR ERP sync — formerly the standalone Fuchs_DataService Windows Service
+        // (Topshelf), now hosted here as a BackgroundService. Gated by Fds:SyncEnabled so
+        // developer machines (appsettings.Development.json sets it false) never poll the ERP;
+        // interval and debug verbosity come from the Fds config section.
+        if (builder.Configuration.GetValue("Fds:SyncEnabled", false))
+        {
+            builder.Services.AddHostedService(sp =>
+            {
+                var mfr = sp.GetRequiredService<fds.IFdsMfr>();
+                var interval = TimeSpan.FromMinutes(
+                    builder.Configuration.GetValue("Fds:ExecutionFrequency_Minutes", 15d));
+                bool debug = builder.Configuration.GetValue("Fds:DebugDetails", false);
+                var jobs = new[]
+                {
+                    new PeriodicJobDefinition("MfrSync", interval, async ct =>
+                    {
+                        await mfr.UpdateIfNecessary_async(debug, ct);
+                        await mfr.UpdateRequested_async(debug, ct);
+                        await mfr.GetInvoiceFiles_async(debug, ct);
+                    })
+                };
+                return new PeriodicHostedService(jobs, sp.GetRequiredService<ILogger<PeriodicHostedService>>());
+            });
+        }
+
         // MVC with Razor view support
         builder.Services.AddControllersWithViews();
+        builder.Services.AddSignalR();
 
         // Fuchs intranet singleton
         builder.Services.AddSingleton(_ => FuchsOcmsIntranet.Instance);
@@ -85,8 +120,19 @@ public class Program
         // Dev/test safety net: Fuchs:Email:OverrideRecipient redirects every outbound email
         // (see appsettings.Development.json) so real tenant-owners/end-customers are never emailed.
         builder.Services.Configure<FuchsEmailSettings>(builder.Configuration.GetSection("Fuchs:Email"));
+        builder.Services.Configure<StartupSelfTestSettings>(builder.Configuration.GetSection("Fuchs:StartupChecks"));
+        // eRechnung (ZUGFeRD/Factur-X) output + external formal-conformance validation seam.
+        builder.Services.Configure<ERechnungSettings>(builder.Configuration.GetSection("Fuchs:ERechnung"));
+        builder.Services.AddSingleton<IERechnungService, ERechnungService>();  // stateless: maps + embeds ZUGFeRD
+        builder.Services.AddSingleton<IERechnungValidator, ProcessWebERechnungValidator>();  // external EN16931 + PDF/A-3 check
+        builder.Services.AddHttpClient(ProcessWebERechnungValidator.HttpClientName,
+            c => c.Timeout = TimeSpan.FromSeconds(90));
         builder.Services.AddHttpClient("ProcessWebMailer");
         builder.Services.AddScoped<IComService, ProcessWebComService>();
+        // Holds the one-shot startup self-test result for the lifetime of the process so the Admin
+        // module can display it as a non-refreshable widget (must be registered before the service).
+        builder.Services.AddSingleton<StartupCheckReporter>();
+        builder.Services.AddHostedService<StartupSelfTestService>();
 
         // Business services (DI migration — replaces the static helper / Active-Record pattern)
         builder.Services.AddSingleton<IBankingService, BankingService>();   // stateless parser
@@ -96,6 +142,25 @@ public class Program
         builder.Services.AddScoped<IReportService, FuchsReportService>();
         builder.Services.AddScoped<IInvoiceService, InvoiceService>();
         builder.Services.AddScoped<IReminderService, ReminderService>();
+        builder.Services.AddScoped<IEventService, EventService>();
+
+        // Read-only system diagnostics for the Admin module (config snapshot + connectivity probes
+        // + test-email). Restricted to fds_sys > 4 in IntranetController.Admin; see the concept doc.
+        builder.Services.AddScoped<ISystemStatusService, SystemStatusService>();
+
+        // Live, backend-authoritative invoice draft editing (ADR 0006): an in-memory
+        // draft cache (singleton), the scoped edit orchestrator, a targeted SignalR
+        // notifier over the dedicated DraftPreviewHub, and the idle-expiry monitor.
+        builder.Services.AddSingleton<IInvoiceDraftCache, InvoiceDraftCache>();
+        builder.Services.AddSingleton<IDraftNotifier, DraftNotifier>();
+        builder.Services.AddScoped<IInvoiceDraftService, InvoiceDraftEditService>();
+        builder.Services.AddHostedService<InvoiceDraftExpiryService>();
+
+        // Live, backend-authoritative reminder draft editing (ADR 0006) — the reminder
+        // mirror of the invoice draft services above, sharing the DraftPreviewHub/notifier.
+        builder.Services.AddSingleton<IReminderDraftCache, ReminderDraftCache>();
+        builder.Services.AddScoped<IReminderDraftService, ReminderDraftEditService>();
+        builder.Services.AddHostedService<ReminderDraftExpiryService>();
 
         // Secondary archive: invoice/reminder PDFs additionally stored in Azure Blob Storage.
         // Disabled by default (Fuchs:AzureStorage:Enabled) — see AzureBlobStorageService.
@@ -141,6 +206,11 @@ public class Program
 
     private static void ConfigureApp(WebApplication app)
     {
+        // OCORE's internal logging helpers (e.g. DatatableWriterAsync's exception logging)
+        // call the static OCORE.Logging.Logger via a null-conditional — without this, those
+        // calls silently no-op instead of reaching Debug output / ErrorLog.txt.
+        OCORE.Logging.Logger = app.Logger;
+
         if (!app.Environment.IsDevelopment())
         {
             app.UseExceptionHandler("/error");
@@ -165,6 +235,8 @@ public class Program
         app.UseRouting();
         app.UseAuthentication();
         app.UseAuthorization();
+        app.MapHub<NotificationHub>("/notifications");
+        app.MapHub<DraftPreviewHub>("/draftpreview");
 
         // Intranet routes (root-level — this IS the website)
         app.MapControllerRoute(

Fuchs/Properties/PublishProfiles/FolderProfile.pubxml

@@ -0,0 +1,20 @@
+<?xml version="1.0" encoding="utf-8"?>
+<!-- https://go.microsoft.com/fwlink/?LinkID=208121. -->
+<Project>
+  <PropertyGroup>
+    <DeleteExistingFiles>true</DeleteExistingFiles>
+    <ExcludeApp_Data>false</ExcludeApp_Data>
+    <LaunchSiteAfterPublish>true</LaunchSiteAfterPublish>
+    <LastUsedBuildConfiguration>Release</LastUsedBuildConfiguration>
+    <LastUsedPlatform>x64</LastUsedPlatform>
+    <PublishProvider>FileSystem</PublishProvider>
+    <PublishUrl>Q:\PWProjects\Fuchs_Intranet</PublishUrl>
+    <WebPublishMethod>FileSystem</WebPublishMethod>
+    <_TargetId>Folder</_TargetId>
+    <SiteUrlToLaunchAfterPublish />
+    <TargetFramework>net10.0</TargetFramework>
+    <RuntimeIdentifier>win-x64</RuntimeIdentifier>
+    <ProjectGuid>2856176d-cda6-1be2-0ce0-d72c26fb4f35</ProjectGuid>
+    <SelfContained>false</SelfContained>
+  </PropertyGroup>
+</Project>