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__setInvoiceCancelled__deprecated.sql

@@ -0,0 +1,22 @@
+
+-- =============================================
+-- Author:		<Author,,Name>
+-- Create date: <Create Date,,>
+-- Description:	<Description,,>
+-- =============================================
+CREATE PROCEDURE [dbo].[fds__setInvoiceCancelled__deprecated]
+	@Id varchar(8),
+	@authuser varchar(25)
+AS
+BEGIN
+	SET NOCOUNT ON;
+	IF [dbo].[fis_getModuleAuth]('fds_inv', @authuser) < 2
+		THROW 60000, N'not authorized', 1;  
+
+	DECLARE @now datetime = GETUTCDATE();
+
+    UPDATE [dbo].[fds__invoices] SET [DateCancelled] = @now, [UserCancelled] = @authuser, [version] = (ISNULL([version],0) + 1)
+	OUTPUT inserted.*
+		WHERE [Id] = @Id AND @Id is not null and [isFinal] = 1 and [IsCanceled] = 0;
+
+END