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/Stored Procedures/fds__setMFRInvoiceFile.sql

@@ -0,0 +1,30 @@
+
+-- =============================================
+-- Author:		<Author,,Name>
+-- Create date: <Create Date,,>
+-- Description:	<Description,,>
+-- =============================================
+CREATE PROCEDURE [dbo].[fds__setMFRInvoiceFile]
+	@Id varchar(15),
+	@filename varchar(100),
+	@file varbinary(max)
+AS
+BEGIN
+	SET NOCOUNT ON;
+	DECLARE @now datetime = GETUTCDATE();
+	DECLARE @Idnum bigint = TRY_CAST(@id as bigint);
+	INSERT INTO [dbo].[fds__admin_activity] ([activity] ,[authuser] ,[info])
+		VALUES ('fds__setMFRInvoiceFile' ,'' , (SELECT * FROM (VALUES(@Id, '')) as z ([id],[authuser]) FOR JSON PATH, INCLUDE_NULL_VALUES, WITHOUT_ARRAY_WRAPPER));
+
+    IF @idnum is not null and NOT EXISTS (SELECT 0 FROM [dbo].[fds__mfr_invoicefiles] WHERE [id] = @id)
+		BEGIN
+			INSERT INTO [dbo].[fds__mfr_invoicefiles]
+					   ([Id]
+					   ,[filename]
+					   ,[file])
+				 VALUES
+					   (@Id
+					   ,@filename 
+					   ,@file)
+		END;
+END