- outboxWorker: remove empty-credential fallback; let loadClientForUser throw on error (CR-03)
- outboxWorker: fix backoff index from nextAttemptCount to row.attemptCount so first retry waits 15s not 60s (WR-01)
- events.ts: replace bare crypto.randomUUID() with import { randomUUID } from 'node:crypto' on all three handlers (WR-08)