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/Security/fuchs_enc_1.sql

@@ -0,0 +1,15 @@
+CREATE SYMMETRIC KEY [fuchs_enc_1]
+    AUTHORIZATION [dbo]
+    WITH ALGORITHM = AES_256
+    ENCRYPTION BY PASSWORD = N'lwppdri?q{jdzus&bkuaheklmsFT7_&#$!~<dhle,zJ,q3th';
+
+
+GO
+GRANT CONTROL
+    ON SYMMETRIC KEY::[fuchs_enc_1] TO [fds_rwe];
+
+
+GO
+GRANT CONTROL
+    ON SYMMETRIC KEY::[fuchs_enc_1] TO [fuchs_rwe];
+