feat: Implement mfr truncation fix and enhance invoice handling

- Added a new SQL script to address the "String or binary data would be truncated" error in mfr sync by widening the Note fields in service objects and companies to NVARCHAR(MAX).
- Updated the table types and associated stored procedures to accommodate the changes, ensuring compatibility with existing data.
- Queued a re-sync for previously rejected rows due to truncation issues.
- Created application logins for fuchs_fds and fuchs_web with placeholder passwords for initial setup.
- Introduced functions for invoice backdating and invoice date retrieval to streamline invoice processing.
- Developed a password generation function with customizable parameters for length and character types.
- Added a random number generation function to support password creation.

Fuchs/Controllers/IntranetController.InvoiceDraft.cs

@@ -3,6 +3,7 @@ using Fuchs.Services;
 using Microsoft.AspNetCore.Mvc;
 using Newtonsoft.Json;
 using Newtonsoft.Json.Linq;
+using static OCORE.SQL.sql;
 using static OCORE.web.mvc_helper_async;
 
 namespace Fuchs.Controllers;
@@ -14,6 +15,20 @@ namespace Fuchs.Controllers;
 // only signals (ADR 0007).
 public partial class IntranetController
 {
+    /// <summary>
+    /// The date the calling user may backdate an invoice to (last working day of the previous month), or
+    /// null when not allowed — fds_inv &gt; 2 and no invoice finalized after that date yet. The SQL function
+    /// is the single source; fds__setInvoiceFinal re-checks it when @backdate = 1 (ADR 0032).
+    /// </summary>
+    private async Task<DateOnly?> GetInvoiceBackdateAsync(string fn, string id, string code)
+    {
+        var val = await getSQLValue_async<string>(
+            "SELECT CONVERT(varchar(10), [dbo].[fds__fn_invoiceBackdate](@authuser), 23);",
+            _intranet.Intranet__SQLConnectionString, "",
+            StdParamlist(), Security: DbSec, options: SqlOpt(fn, id, code));
+        return InvoiceDates.ParseBackdate(val.Result);
+    }
+
     /// <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" });
 
@@ -71,7 +86,8 @@ public partial class IntranetController
         return await JSONAsync(new { ok = true, version = session.Version });
     }
 
-    // POST inv/dpreview — { token } → { img[], total } (rendered straight from the cache)
+    // POST inv/dpreview — { token } → { img[], total, backdate } (rendered straight from the cache).
+    // backdate ("yyyy-MM-dd" or null) drives the admin-only "Rechnungsdatum Vormonat" checkbox (ADR 0032).
     private async Task<IActionResult> HandleDraftPreview(string fn, string id, string code)
     {
         if (!HasForm("token")) return BadRequest400();
@@ -81,7 +97,8 @@ public partial class IntranetController
             var doc = await _invoiceDrafts.RenderPreviewAsync(token);
             if (doc == null) return DraftGone();
             var imgcol = await _pdf.DocToImageCollectionAsync(doc);
-            return await JSONAsync(new { img = imgcol.ImgB64Array, total = imgcol.TotalPages });
+            DateOnly? backdate = await GetInvoiceBackdateAsync(fn, id, code);
+            return await JSONAsync(new { img = imgcol.ImgB64Array, total = imgcol.TotalPages, backdate = backdate?.ToString("yyyy-MM-dd") });
         });
     }
 

Fuchs/Controllers/IntranetController.Invoices2.cs

@@ -16,10 +16,22 @@ namespace Fuchs.Controllers;
 // Partial class: Invoice sub-handlers
 public partial class IntranetController
 {
+    /// <summary>True when <paramref name="raw"/> is an mfr invoice id (positive integer); Intranet-created
+    /// invoices use alphanumeric ids and have no mfr entity to reset.</summary>
+    internal static bool TryGetMfrInvoiceId(string? raw, out long mfrId)
+        => long.TryParse(raw?.Trim(), NumberStyles.None, CultureInfo.InvariantCulture, out mfrId) && mfrId > 0;
+
     private async Task<IActionResult> HandleInvoicePget(string fn, string id, string code)
     {
         if (!HasForm("id")) { _logger.LogWarning("HandleInvoicePget: missing 'id' form field user={User}", UserAccountID); return BadRequest400(); }
-        if (!long.TryParse(Form("id"), out long tgtid)) { _logger.LogWarning("HandleInvoicePget: invalid 'id' value='{Value}' user={User}", Form("id"), UserAccountID); return BadRequest400(); }
+        if (!TryGetMfrInvoiceId(Form("id"), out long tgtid))
+        {
+            // Intranet-created invoices carry an alphanumeric Id (fds__fn_invoice_id) and have no mfr
+            // entity to reset. Both storno paths call pget first, so rejecting them here (400) left the
+            // storno window empty. Legacy parity: skip the mfr reset and report success.
+            _logger.LogDebug("HandleInvoicePget: non-mfr invoice id='{Value}', nothing to reset user={User}", Form("id"), UserAccountID);
+            return await JSONAsync(new { ok = true });
+        }
         _logger.LogDebug("HandleInvoicePget tgtid={TgtId} user={User}", tgtid, UserAccountID);
 
         using (var mfr = _mfrFactory.Create())
@@ -263,6 +275,16 @@ public partial class IntranetController
         return await JSONAsync(new { payments = sqldt.Tables("items").toArrayofObjectDictionaries() });
     }
 
+    /// <summary>
+    /// DATEV overview (<c>inv/datev</c>). Parameters are bound by name: the proc's signature is
+    /// (@tgtdate, @mode, @files, @authuser) and the former positional call put @authuser into
+    /// @files and never supplied @authuser, so every call failed. @files = 0 — the overview needs
+    /// no PDF bytes. Result sets in proc order: header, invoice documents, bookings, debtors.
+    /// </summary>
+    internal const string DatevOverviewSql =
+        "EXECUTE [dbo].[fds__getDatevExports] @tgtdate = @tgtdate, @mode = @mode, @files = 0, @authuser = @authuser;";
+    internal static readonly string[] DatevOverviewTables = { "admin", "files", "invoices", "debits" };
+
     private async Task<IActionResult> HandleDatev(string fn, string id, string code)
     {
         if (!DateTime.TryParseExact(Form("tgt"), "yy-MM-dd",
@@ -274,10 +296,10 @@ public partial class IntranetController
         string mode = Form("mode").ne("m");
         _logger.LogDebug("HandleDatev tgtdate={TgtDate} mode={Mode} user={User}", tgtdate.ToString("yy-MM-dd"), mode, UserAccountID);
         var dset = await getSQLDataSet_async(
-            "EXECUTE [dbo].[fds__getDatevExports] @tgtdate, @mode, @authuser;",
+            DatevOverviewSql,
             _intranet.Intranet__SQLConnectionString,
             StdParamlist(SQL_Date("@tgtdate", tgtdate), SQL_VarChar("@mode", mode)),
-            tablenames: new[] { "files", "invoices", "debits" },
+            tablenames: DatevOverviewTables,
             Security: DbSec, options: SqlOpt(fn, id, code));
         _logger.LogDebug("HandleDatev tgtdate={TgtDate} files={FileCount} invoices={InvCount} user={User}",
             tgtdate.ToString("yy-MM-dd"), dset.Tables("files").Rows.Count, dset.Tables("invoices").Rows.Count, UserAccountID);
@@ -465,7 +487,10 @@ public partial class IntranetController
                         ["NameOrNumber"] = "",
                         ["htmltext"]   = d["Text"],
                         ["position"]   = d["Position"],
-                        ["SortOrder"]  = d["SortOrder"]
+                        ["SortOrder"]  = d["SortOrder"],
+                        // Round-trips the referenced invoice (CanceledInvoice / IntInvoiceAllocation) so a
+                        // re-saved draft keeps it — fds__setInvoiceFinal needs it for Replaces/allocations.
+                        ["reference_InvId"] = d.nz("reference_InvId") is { Length: > 0 } refId ? refId : null
                     });
                 }
                 sdic["items"] = itm;

Fuchs/Controllers/IntranetController.Requests.cs

@@ -1,5 +1,6 @@
 using System.Globalization;
 using Fuchs.intranet;
+using Fuchs.Observability;
 using Fuchs.Services;
 using Microsoft.AspNetCore.Mvc;
 using Microsoft.Data.SqlClient;
@@ -302,14 +303,41 @@ public partial class IntranetController
     private async Task<IActionResult> HandleRequestSconf(string fn, string id, string code)
     {
         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);
+        // Admin option: date the invoice to the last working day of the previous month (ADR 0032).
+        // fds__setInvoiceFinal re-validates (fds_inv > 2, no later invoice) and throws otherwise.
+        bool backdate = InvoiceDates.IsBackdateRequested(Form("backdate"));
+        _logger.LogInformation("HandleRequestSconf: finalizing invoice {InvId} backdate={Backdate} user={User}", Form("id"), backdate, UserAccountID);
         var dt    = await getSQLDatatable_async(
-            "EXECUTE [dbo].[fds__setInvoiceFinal] @Id, @authuser;",
+            "EXECUTE [dbo].[fds__setInvoiceFinal] @Id, @authuser, @backdate;",
             _intranet.Intranet__SQLConnectionString,
-            StdParamlist(SQL_VarChar("@Id", Form("id"))),
+            StdParamlist(SQL_VarChar("@Id", Form("id")), SQL_Bit("@backdate", backdate)),
             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);
+            _logger.LogError("HandleRequestSconf: SQL error {SqlErrorNumber} finalizing invoice {InvId}: {SqlError}, user={User}", dt.ExceptionCode, Form("id"), dt.Exception, UserAccountID);
+        // Only SQL error 60001 is a backdate rejection. A 0-row result means the invoice is already
+        // final/sent (double submit) — it must not be reported as "create it again without backdating".
+        var outcome = InvoiceDates.ClassifyFinalizeResult(dt.Exception, dt.ExceptionCode, dt.Count);
+        if (backdate)
+        {
+            FuchsTelemetry.InvoicesBackdated.Add(1, new KeyValuePair<string, object?>("outcome", InvoiceDates.OutcomeTag(outcome)));
+            if (outcome == InvoiceFinalizeOutcome.Finalized)
+                _logger.LogInformation(new EventId(0, "InvoiceBackdated"),
+                    "Invoice {InvId} finalized with backdated invoice date {DateFinalized} user={User}",
+                    Form("id"), dt.FirstRow.toObjectDictionary().nz("DateFinalized"), UserAccountID);
+        }
+        switch (outcome)
+        {
+            case InvoiceFinalizeOutcome.BackdateNotAllowed:
+                return await InvoiceIssueResult(
+                    "Die Rechnung wurde nicht erstellt: Das Rechnungsdatum kann nicht mehr auf den Vormonat gesetzt werden (es wurde bereits eine Rechnung im neuen Monat erstellt). Bitte ohne Rückdatierung erneut erstellen.",
+                    Form("id"));
+            case InvoiceFinalizeOutcome.AlreadyFinal:
+                return await InvoiceIssueResult(
+                    "Die Rechnung ist bereits abgeschlossen oder versendet und wurde nicht erneut erstellt.",
+                    Form("id"));
+            case InvoiceFinalizeOutcome.Error:
+                return await InvoiceIssueResult("Die Rechnung konnte aufgrund eines Fehlers nicht erstellt werden.", Form("id"));
+        }
         var frdic = dt.FirstRow.toObjectDictionary();
         if (frdic.TryGetValue("IsFinal", out var isFinal) && isFinal is true)
         {