Add Fuchs_Database SSDT project (schema source of truth)

Adds the SQL Server Data Tools project for the fuchs_fds database — tables,
table types, functions and stored procedures that the backend calls (e.g.
fds__getInvoice, fds__merge_bankingtransactions, fds__tt__bankingtransactions,
fds__admin_getReportCatalog, fis_* auth). Build/model caches (bin, obj,
*.dbmdl, *.jfm, *.user) are git-ignored.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

Fuchs_Database/dbo/Tables/fds__admin_dberrors.sql

@@ -0,0 +1,12 @@
+CREATE TABLE [dbo].[fds__admin_dberrors] (
+    [ErrorID]        INT           IDENTITY (1, 1) NOT NULL,
+    [UserName]       VARCHAR (100) NULL,
+    [ErrorNumber]    INT           NULL,
+    [ErrorState]     INT           NULL,
+    [ErrorSeverity]  INT           NULL,
+    [ErrorLine]      INT           NULL,
+    [ErrorProcedure] VARCHAR (MAX) NULL,
+    [ErrorMessage]   VARCHAR (MAX) NULL,
+    [ErrorDateTime]  DATETIME      NULL
+);
+