feat(p9): IiosDlqItem + DlqService (dead-letter + deterministic replay)
Task D.1: mandated dlq_item table (sourceType/sourceId/failureStage/errorCode/
retryCount/payloadRef/consumerName/scopeId/status). DlqService.record (idempotent
per consumer+sourceId, bumps retryCount), onConsumerFailure (quarantine + clear the
IiosProcessedEvent claim so it's replayable — fixes claim-then-fail), registerHandler
+ replay (clears claim, awaits the registered consumer handler → RESOLVED on success,
QUARANTINED+retry on repeat throw; outbox-sourced items reset to PENDING). Wired into
OutboxModule; resetDb truncates it. 3 tests.
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
maaz519
208fb0b4f0