Add unit tests for Fuchs_DataService and related components

- Introduced comprehensive unit tests for the Fuchs_DataService library, covering DATEV header formatting, CSV/XML generation, and FdsMfrClient construction.
- Implemented tests for FdsMfr.UpdateNeed parsing and FdsShared utility helpers, ensuring correct functionality and stability.
- Added tests for FdsConfig and FdsMfrClient to validate configuration resolution and client construction.

Document decisions on backend-authoritative invoice and reminder handling

- Created ADR 0008 to clarify that all invoice types and reminder stages are backend-authoritative during drafting and previewing.
- Established that all calculations and settings must be processed server-side, ensuring consistency between online editor and PDF outputs.

Define irreversible mutations for set-price modes in invoices

- Documented ADR 0009 to specify that the "Set mit Preis" and "Nur Set mit Preis" operations are irreversible mutations affecting service request blocks.
- Clarified that these operations are not display toggles but actual data changes, ensuring clear expectations for invoice handling.

Transition MFR ERP sync to in-process execution within the web app

- Created ADR 0010 to outline the migration of Fuchs_DataService from a standalone service to an in-process library within the Fuchs web application.
- Updated configuration and logging management to be handled by the host application, streamlining the sync process.

Add publish profile and periodic hosted service for job scheduling

- Introduced a publish profile for deployment to a specified folder.
- Implemented PeriodicHostedService to manage multiple independent jobs, including the MFR ERP sync, with configurable execution intervals.

Add dotnet-tools.json for EF Core CLI tools

- Included dotnet-tools.json to manage the version of dotnet-ef for Entity Framework Core migrations and commands.

Fuchs_DataService/Fuchs_DataService.xml

@@ -18,38 +18,10 @@
         </member>
         <member name="T:fds.FdsConfig">
             <summary>
-            Holds the application <see cref="T:Microsoft.Extensions.Configuration.IConfiguration"/> built from appsettings.json.
-            Call <see cref="M:fds.FdsConfig.Initialize"/> once at startup before accessing <see cref="P:fds.FdsConfig.Current"/>.
-            </summary>
-        </member>
-        <member name="T:fds.Logging.FdsLoggerProvider">
-            <summary>
-            Writes log entries to Debug output and a rolling file.
-            Database logging is wired up but disabled — set <see cref="P:fds.Logging.FdsLoggerProvider.DatabaseLoggingEnabled"/> to true to activate.
-            </summary>
-        </member>
-        <member name="P:fds.Logging.FdsLoggerProvider.DatabaseLoggingEnabled">
-            <summary>Set to true to activate database logging via fds__admin_logdebug.</summary>
-        </member>
-        <member name="M:fds.Logging.FdsLogger.WriteToDatabase(System.String,System.String,System.Exception)">
-            <summary>
-            Prepared DB logging via fds__admin_logdebug.
-            Enable by setting <see cref="P:fds.Logging.FdsLoggerProvider.DatabaseLoggingEnabled"/> = true.
-            </summary>
-        </member>
-        <member name="T:fds.PeriodicJobDefinition">
-            <summary>
-            Defines a named job with its own execution schedule for use with <see cref="T:fds.PeriodicHostedService"/>.
-            </summary>
-        </member>
-        <member name="M:fds.PeriodicJobDefinition.#ctor(System.String,System.TimeSpan,System.Func{System.Threading.CancellationToken,System.Threading.Tasks.Task})">
-            <summary>
-            Defines a named job with its own execution schedule for use with <see cref="T:fds.PeriodicHostedService"/>.
-            </summary>
-        </member>
-        <member name="T:fds.PeriodicHostedService">
-            <summary>
-            A <see cref="T:Microsoft.Extensions.Hosting.BackgroundService"/> that runs multiple independent jobs, each on its own <see cref="T:System.Threading.PeriodicTimer"/>.
+            Holds the application <see cref="T:Microsoft.Extensions.Configuration.IConfiguration"/> supplied by the host (the Fuchs web app).
+            Fuchs_DataService is a library — it has no configuration of its own; the host owns the
+            connection strings and MFR credentials and injects them via <see cref="M:fds.FdsConfig.Initialize(Microsoft.Extensions.Configuration.IConfiguration)"/>,
+            which <c>Program.cs</c> calls once at startup before any <see cref="T:fds.FdsMfr"/> use.
             </summary>
         </member>
     </members>