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__companies.sql

@@ -0,0 +1,22 @@
+CREATE TABLE [dbo].[mfr__companies] (
+    [Id]                     BIGINT         NOT NULL,
+    [Location#ID]            BIGINT         NULL,
+    [Version]                INT            NOT NULL,
+    [IsPhysicalPerson]       BIT            NOT NULL,
+    [IsOwner]                BIT            NOT NULL,
+    [IsEmailInvoicingActive] BIT            NOT NULL,
+    [IsSupplier]             BIT            NOT NULL,
+    [MappingId]              NVARCHAR (255) NULL,
+    [ExternalId]             NVARCHAR (255) NULL,
+    [Name]                   NVARCHAR (255) NULL,
+    [Note]                   NVARCHAR (255) NULL,
+    [SupportTelephone]       NVARCHAR (255) NULL,
+    [SupportFax]             NVARCHAR (255) NULL,
+    [SupportMail]            NVARCHAR (255) NULL,
+    [QuickSearch]            NVARCHAR (255) NULL,
+    [DateModified]           DATETIME       NOT NULL,
+    [CustomValues]           NVARCHAR (MAX) NULL,
+    [MainContactId]          BIGINT         NULL,
+    CONSTRAINT [PK_mfr__company] PRIMARY KEY CLUSTERED ([Id] ASC)
+);
+