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/Tables/tmp__fds__invoice_servicerequests.sql

@@ -0,0 +1,15 @@
+CREATE TABLE [dbo].[tmp__fds__invoice_servicerequests] (
+    [Id]                  BIGINT          NOT NULL,
+    [InvRqId]             VARCHAR (10)    NOT NULL,
+    [InvId]               VARCHAR (10)    NOT NULL,
+    [mfr__servicerequest] BIGINT          NULL,
+    [title]               NVARCHAR (MAX)  NULL,
+    [value_net]           NUMERIC (10, 2) NULL,
+    [SortOrder]           TINYINT         NOT NULL
+);
+
+
+GO
+CREATE UNIQUE NONCLUSTERED INDEX [IX_tmp__fds__invoice_servicerequests]
+    ON [dbo].[tmp__fds__invoice_servicerequests]([InvRqId] ASC);
+