23e2ae9eb4
- ThreadIndexEntry gains status and completedAt fields - createThreadIndexEntry defaults to idle/null - normalizeThreadIndexEntry backward-compat defaults - updateThreadHead resets to idle (衔尾蛇 resume prep) - markThreadSuspended sets status=suspended - New markThreadCompleted(entry, status, now) function - serializeThreadIndexEntry includes new fields Part of #39, closes #40