- Remove hardcoded SQL comments containing 'ml_user' and 'ml_password'
- Remove fallback default credentials in DATABASE_URL construction
- Add fail-fast validation: raise RuntimeError if DATABASE_URL env var is missing or empty
- Mark task 1.4 as complete in code-review-fix/tasks.md
- Replace ml_password with change_me_to_a_strong_password placeholder
- Replace ml_user with your_db_user placeholder
- Mark task 1.3 as completed in tasks.md
Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>