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__r_getBalanceByMonth.sql

@@ -0,0 +1,53 @@
+-- =============================================
+-- Author:		<Author,,Name>
+-- Create date: <Create Date,,>
+-- Description:	<Description,,>
+-- =============================================
+CREATE PROCEDURE [dbo].[fds__r_getBalanceByMonth]
+	@authuser varchar(100)
+AS
+BEGIN
+	SET NOCOUNT ON;
+
+    DECLARE @today date = GETDATE()
+	DECLARE @tomorrow date = DATEADD(DAY,1,@today);
+
+	IF [dbo].[fis_getModuleAuth]('fds_reports', @authuser) < 2
+		THROW 60000, N'not authorized', 1;  
+
+
+	DECLARE @Admin [dbo].[fds__tt__admin_ReportAdminTable];
+
+	--Admin Table
+	INSERT INTO @Admin
+	VALUES (
+		'bbm'
+		,'Umsatz nach Monaten'
+		,'Umsatz nach Monaten'
+		,'' + FORMAT(GETDATE(), 'yyyy-MM-dd HH:mm')
+		,''
+		,'table' --typ
+		, ''  --settings
+		, ''
+		, 0)
+
+	SELECT * FROM @Admin;
+
+	WITH inv as (
+		SELECT 
+				[Dateofcreation] = i.[DateCreatEd]
+				,i.[InvoiceBalance]
+				,[InvoiceBalanceNetto] = i.[InvoiceBalance_net]
+			FROM [dbo].[fds__invoices] as i 
+			WHERE i.[isFinal] = 1
+	)
+	SELECT 
+		[Monat] = FORMAT( inv.[Dateofcreation], 'yyyy - MM', 'de')
+		, [∑ Umsätze] = FORMAT(  SUM(  ISNULL(inv.[InvoiceBalance],0) ), '#,0.00 €', 'de')
+		, [style:∑ Umsätze]  = 'text-align: right'
+		, [∑ Umsätze_netto] = FORMAT(  SUM(  ISNULL(inv.[InvoiceBalanceNetto],0) ), '#,0.00 €', 'de')
+		, [style:∑ Umsätze_netto]  = 'text-align: right'
+	FROM inv
+	GROUP BY FORMAT( inv.[Dateofcreation], 'yyyy - MM', 'de');
+
+END