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__maint__updateCancelledStatus.sql

@@ -0,0 +1,41 @@
+-- =============================================
+-- Author:		<Author,,Name>
+-- Create date: <Create Date,,>
+-- Description:	<Description,,>
+-- =============================================
+CREATE PROCEDURE [dbo].[fds__maint__updateCancelledStatus]
+	
+AS
+BEGIN
+	SET NOCOUNT ON;
+
+	DECLARE @now datetime = GETUTCDATE();
+	DECLARE @log varchar(100) = 'DateCancelled Set: ' + FORMAT(@now,'yyyy-MM-ddTHH:mm:ssZ') + ';'
+	DECLARE @out TABLE([InvId]  varchar(10), [log] varchar(100));
+
+    --select [id],[invoiceid],[DocumentName],[IsCanceled],[datefinalized]
+	UPDATE inv 
+		SET inv.[Version] = inv.[version] + 1
+			, inv.[DateCancelled] = storno_inv.[DateFinalized]
+			, inv.[UserCancelled] = storno_inv.[UserFinalized]
+	OUTPUT inserted.id, @log
+		INTO @out
+	FROM [dbo].[fds__invoices] as inv
+		JOIN fds__invoice_details as storno_details on storno_details.[StornoTo_InvId] = inv.[id]
+		JOIN fds__invoices as storno_inv on storno_details.[InvId] = storno_inv.[id] and storno_inv.[isFinal] = 1 and storno_inv.[datefinalized] is not null
+	WHERE inv.[IsCanceled] = 0
+		AND inv.[DateCancelled] is null
+	;
+
+
+	MERGE [dbo].[fds__invoice_details] as TARGET
+		USING @out as SRC ON TARGET.[InvID] = SRC.[InvId]
+	WHEN MATCHED THEN
+		UPDATE 
+			SET TARGET.[log] = ISNULL(TARGET.[log], '') + SRC.[log]
+	WHEN NOT MATCHED BY TARGET THEN 
+		INSERT ([InvId] ,[log])
+		VALUES (SRC.[InvId], SRC.[log])
+	;
+
+END