technical-design-quality-review

sequence.md v6 describes two gaps against Q1: a retry without a stable operation key can cause duplicate debits, and broker failure after the ledger commit can leave the debit unreconciled to order state. Decide on stable-key idempotency and transactional outbox or equivalent reconciliation, then validate the isolated step-3 failure and record owner and closure evidence. No implementation or runtime behavior was examined.