- All 4 repos mirror the SQLite contracts using PG-native types
(UUID, BYTEA, JSONB, BIGSERIAL, TIMESTAMPTZ, SMALLINT)
- audit_no_modify() trigger refuses UPDATE/DELETE/TRUNCATE on audit_events
- pg_advisory_xact_lock for cross-process row locking
- Integration tests verify trigger fires correctly on tamper attempt
- Test cleanup helper temporarily disables trigger to reset between specs
- 4 integration specs all green against PostgreSQL 16