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/Functions/fds__fn_requestsforinvoice.sql

@@ -0,0 +1,26 @@
+-- =============================================
+-- Author:		<Author,,Name>
+-- Create date: <Create Date,,>
+-- Description:	<Description,,>
+-- =============================================
+CREATE FUNCTION [dbo].[fds__fn_requestsforinvoice]
+(	
+	
+)
+RETURNS TABLE 
+AS
+RETURN 
+(
+	SELECT 
+		 [Id]
+		 ,sreq.[ExternalId]
+		 ,sreq.[Name]
+		 ,sreq.[workdoneat]
+		 ,sreq.[ReleasedAt]
+		 ,sreq.[CustomerId]
+	FROM [dbo].[mfr__servicerequests] as sreq 
+		WHERE [state] not in ('Closed')
+			AND [type] in ('IsProject', 'IsMaintenance')
+			AND EXISTS (SELECT 0 FROM dbo.[mfr__*PartnerSet] as ps WHERE ps.[Property] = 'ServiceRequest:Tags' and ps.[PartnerId] = '16034758659' and sreq.[id] = ps.[EntityId])
+			AND NOT EXISTS( SELECT 0 FROM [dbo].[fds__invoice_servicerequests] as isr join [dbo].[fds__invoices] as inv on isr.[InvId] = inv.[id] and isr.[mfr__servicerequest] = sreq.[id]) 
+)