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_bankingtransactions_perInvoice.sql

@@ -0,0 +1,35 @@
+
+-- =============================================
+-- Author:		<Author,,Name>
+-- Create date: <Create Date,,>
+-- Description:	<Description,,>
+-- =============================================
+CREATE FUNCTION [dbo].[fds__fn_bankingtransactions_perInvoice]
+(
+	@startdate date = NULL
+	,@enddate date = NULL
+)
+RETURNS @bankingtransactions TABLE
+(
+	
+	[InvId] varchar(15)
+	,[Amount] numeric(9,2)
+	,[manu] bit
+)
+AS
+BEGIN
+	-- Fill the table variable with the rows for your result set
+	
+	DECLARE @invoice_idlist [dbo].[fds__tt__idlist_vchar];
+	
+	INSERT INTO @bankingtransactions
+	SELECT 
+		[invid]
+		, [amount] = SUM(ISNULL([amount], 0.0))
+		, [manu] = CAST(MAX(ISNULL(CAST([manu] as int),0)) as bit)
+	FROM dbo.fds__fn_bankingtransactions(null, null, @startdate, @enddate, @invoice_idlist)   -- start and enddates will filter by invoice date and not by banking transactions' value dates
+	GROUP BY [invid];
+
+
+	RETURN 
+END