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_admin_debuglog.sql

@@ -0,0 +1,18 @@
+CREATE TABLE [dbo].[fis_admin_debuglog] (
+    [uid]              INT            IDENTITY (1, 1) NOT NULL,
+    [machine]          VARCHAR (50)   NULL,
+    [type]             VARCHAR (10)   NULL,
+    [url]              VARCHAR (255)  NULL,
+    [uniquekey]        VARCHAR (5)    NULL,
+    [authuser]         VARCHAR (5)    NULL,
+    [query]            VARCHAR (MAX)  NULL,
+    [form / content]   NVARCHAR (MAX) NULL,
+    [server_variables] VARCHAR (MAX)  NULL,
+    [cookies]          VARCHAR (MAX)  NULL,
+    [authcookie]       VARCHAR (MAX)  NULL,
+    [files]            VARCHAR (MAX)  NULL,
+    [isdebug]          BIT            NULL,
+    [timestamp]        DATETIME       NULL,
+    CONSTRAINT [PK_fis_admin_debuglog] PRIMARY KEY CLUSTERED ([uid] ASC)
+);
+