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/fis_module_auth.sql

@@ -0,0 +1,10 @@
+CREATE TABLE [dbo].[fis_module_auth] (
+    [id]            BIGINT       IDENTITY (1, 1) NOT NULL,
+    [account]       VARCHAR (50) NULL,
+    [module]        VARCHAR (50) NOT NULL,
+    [group_or_user] VARCHAR (5)  NOT NULL,
+    [isgroup]       BIT          NOT NULL,
+    [auth]          INT          CONSTRAINT [DF_fis_module_auth_auth] DEFAULT ((1)) NOT NULL,
+    CONSTRAINT [PK_fis_module_auth] PRIMARY KEY CLUSTERED ([id] ASC)
+);
+