The relay only looked at published_at and ignored the ADR-002 §2.1 columns
added in db 0002_foundation: rows stayed status='pending' forever after
dispatch, failures were retried every tick without backoff, and the
row-level idempotency_key was never used as the engine enqueue key.
- claim status='pending' AND next_attempt_at<=now()
- enqueue with idempotency_key (fallback outbox:<id>)
- success: status=dispatched, published_at, attempts+1
- failure: attempts+1, exponential backoff (cap 5 min), last_error; dead at maxAttempts
- test helper table now mirrors db 0001+0002; tests cover backoff and dead
Co-Authored-By: Claude Fable 5.1 <[email protected]>
