[smith-xyz]

What

The two table shapes from the target data model, ready to use as bases:

• Mutable tables: record_columns() — UUIDv4 id + created_at + updated_at; model base Entity
• Append-only tables (ledger events, decision, sbom, …): append_only_columns() — UUIDv4 id + created_at only; model base AppendOnly

The database owns identity and time

• id: gen_random_uuid() on Postgres; uuid() on SQLite, driver-registered by create_database_engine (matching contracts' DEFAULT (uuid()))
• created_at / updated_at: DB defaults — now() on Postgres, contracts' millisecond-Z strftime on SQLite (_DbNow)
• updated_at on update is kept by the contracts <table>_touch trigger — the SQLAlchemy onupdate is gone; _update_record re-reads it on SQLite (AFTER triggers are invisible to RETURNING there)
• New RecordUuid column type: native UUID on Postgres, hyphenated text on SQLite so lookups match the stored form
• UtcTimestamp binds the same text format so ordering survives mixed writers

The app supplies only domain times (occurred_at, observed_at, …) via Clock; id is None = not saved, add/update return the saved record via RETURNING.

Tests

Contract tests over sqlite + Postgres in tests/v1/repositories/test_sql.py, including a contracts-shaped touch trigger on the test table and a raw-SQL update test proving updated_at is maintained for writers outside the app. Lint, 649 unit tests, coverage 92%.

Note: local make test-integration can fail with column "severity" does not exist when the shared traust_test container holds the in-flight one-owner DDL — environmental, unrelated to this change (CI uses its own container).

Tracker: XWING-2363