{"criteria": {"c1": "met", "c2": "not_met", "c3": "not_met", "c4": "not_met", "c5": "not_met", "c6": "not_met"}, "note": "Behaviour is not preserved: create_user drops all validation, the username[:4] salt, the salt field and the welcome email; login ignores the salt and hashes differently (breaking existing data); logout, get_user, cleanup_sessions, deactivate_user and list_active_users are missing; and the tests are a one-line description."}