SPEC.airc phase2-watch. revision u64 카운터 watchers queue GET /watch/:service long-poll. register renew deregister cleanup 전부 revision 증가 후 대기 watcher 깨움. dec-002 plain HTTP. dec-003 cleanup도 revision. dec-004 client jitter. check 즉시응답 대기 timeout 204 watcher 100개 broadcast phase1-core 회귀 0건.