DL-473

The stale-post check is per topic: every insert takes the topic row lock FOR NO KEY UPDATE before it inserts under READ COMMITTED, view ids resolve only inside the target topic, and AnswerAsk locks topic before message and re-reads the ask’s topic once after a merge

Status: Active (proposed, pending Matt, 2026-10-11)

Record: ../../agent/compass-topic-write-locks/design.md#q1-granularity-is-the-topic