Datasets:
| # CROSS2: Schema Evolution (Brief) | |
| Service A deployed a database schema migration that breaks Service B. The Planner has | |
| analyzed the migration and identified all changes needed in Service B. | |
| 1. Update `service_b/models.py` to match the new schema | |
| 2. Fix `service_b/queries.py` — eliminate all `SELECT *` | |
| 3. Implement `scripts/backfill.py` using the Planner's default values | |
| Run `pytest tests/` to verify. | |