Covers the question/answer lifecycle: answers restricted to offered labels, delivery resolving the question and muting its re-report, failed deliveries keeping the question for retry, queued answers withdrawable until delivered, stale acknowledgements ignored, and an undelivered pick dying with the question it answered.

## Before writing SPEC.md files

Read https://raw.githubusercontent.com/brillout/sdd/refs/heads/main/sdd.md
