<objective A migration that passes can still silently drop a column's data, and an assertion that never fails will green-light a query that lost its index — both ship to production looking fine. This skill produces database tests that catch those: forward AND backward migration tests, constraint-rejection tests, deterministic seed data, drift detection, and query-plan assertions that actually fail when the index disappears. Before starting: check for database type, ORM, migration tooling, and environment config — they shape every pattern below. </objective --- Discovery Questions Check first…