digitimes updates registry/index incrementally while still fetching, so a
mid-fetch registry write was misread as 推送/收尾 and overrode the agent's
own correct 采集中 heartbeat. Disk inference has now been wrong in both
directions (stale when the agent forgets to flip,超前 on incremental
writers) — trust the agent's heartbeat whenever present; disk evidence
and neutral 运行中 remain fallbacks only.