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/fis_getModuleAuthList.sql

@@ -0,0 +1,20 @@
+-- =============================================
+-- Author:		<Author,,Name>
+-- Create date: <Create Date,,>
+-- Description:	<Description,,>
+-- =============================================
+CREATE FUNCTION [dbo].[fis_getModuleAuthList]
+(	
+	@module varchar(100)
+	,@authuser varchar(10)
+)
+RETURNS TABLE 
+AS
+RETURN 
+(
+	SELECT 
+		[module] = [value]
+		, [auth] = [dbo].[fis_getModuleAuth]([value], @authuser)
+	FROM string_split(ISNULL(@module, ''),',') 
+	WHERE TRIM([value]) <> ''
+)