Fix DB Model.

migrations/remove_email_preferences.sql

@@ -1,7 +1,8 @@
--- Remove all email preference columns from user_preferences table
--- These columns were not being used and are being removed to clean up the schema
+-- Remove unused columns from user_preferences table
+-- These columns were defined in the model but never used in the application
 
 ALTER TABLE user_preferences 
     DROP COLUMN IF EXISTS email_daily_summary,
     DROP COLUMN IF EXISTS email_notifications,
-    DROP COLUMN IF EXISTS email_weekly_summary;
+    DROP COLUMN IF EXISTS email_weekly_summary,
+    DROP COLUMN IF EXISTS default_project_id;