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/mfr___PartnerSet.sql

@@ -0,0 +1,25 @@
+CREATE TABLE [dbo].[mfr__*PartnerSet] (
+    [Property]    VARCHAR (50) NOT NULL,
+    [PartnerType] VARCHAR (25) NOT NULL,
+    [PartnerId]   BIGINT       NOT NULL,
+    [EntityId]    BIGINT       NOT NULL
+);
+
+
+GO
+CREATE NONCLUSTERED INDEX [mfr__*PartnerSet__ix3]
+    ON [dbo].[mfr__*PartnerSet]([Property] ASC, [PartnerId] ASC)
+    INCLUDE([EntityId]);
+
+
+GO
+CREATE NONCLUSTERED INDEX [mfr__*PartnerSet__ix2]
+    ON [dbo].[mfr__*PartnerSet]([EntityId] ASC, [Property] ASC)
+    INCLUDE([PartnerId]);
+
+
+GO
+CREATE NONCLUSTERED INDEX [mfr__*PartnerSet__ix1]
+    ON [dbo].[mfr__*PartnerSet]([Property] ASC)
+    INCLUDE([PartnerId], [EntityId]);
+