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/backup__fds__getInvoiceReminder.sql

@@ -0,0 +1,43 @@
+-- =============================================
+-- Author:		<Author,,Name>
+-- Create date: <Create Date,,>
+-- Description:	<Description,,>
+-- =============================================
+CREATE PROCEDURE [dbo].[backup__fds__getInvoiceReminder]
+	@InvId varchar(15)
+	, @include_drafts bit = 0
+	,@authuser varchar(25)
+AS
+BEGIN
+	SET NOCOUNT ON;
+
+	With inv as (
+		SELECT TOP(1) 
+			[Id] = CAST([id] as varchar(15)), [InvoiceId], [DocumentName]
+		FROM [dbo].[fds__invoices] 
+		WHERE [id] = @InvId
+	), inv2 as(
+		SELECT * FROM inv
+		UNION
+		SELECT TOP(1) 
+			[Id] = CAST([id] as varchar(15)), [InvoiceId], [DocumentName]
+		FROM [dbo].[mfr__invoices] as mi
+		WHERE NOT EXISTS( SELECT 0 FROM inv )
+			AND TRY_CAST(@InvId as bigint) is not null 
+			AND mi.[id] = TRY_CAST(@InvId as bigint)
+	)
+    SELECT rem.[Id]
+			,rem.[DateSent]
+			,[status]		= CAST(CASE WHEN rem.[isSent] = 1 THEN 'versandt' WHEN rem.[isfinal] = 1 THEN 'fertig' WHEN rem.isfinal = 0 THEN 'Entwurf' ELSE ''  END AS  varchar(50))
+			,rem.[subject]
+			,rem.[DocumentName]
+			,rem.[amount_open]
+			,rem.[InvId]
+			,[InvoiceId]	= inv2.[InvoiceId]
+			--,[InvoiceDocumentName] = inv2.[DocumentName]
+			,[hasFile]		= cast( IIF(rem.[file] is null, 0, 1) as bit)
+		FROM [dbo].[fds__reminder] as rem 
+			LEFT JOIN inv2 on rem.[InvId] = inv2.[Id]
+		WHERE [invId] = @InvId;
+
+END