feat: periodic health checks — gateway heartbeat and system checks

[maxdraki]

Problem

The Health tab currently only shows a single gateway entry, timestamped at the last gateway restart. The hook only calls sendHealth() on gateway:startup — there are no periodic checks, so the tab goes stale immediately.

Goal

Health tab should reflect live system status, updated every few minutes, with meaningful checks beyond just "did the gateway start".

Proposed checks

Check	Source	Frequency	Healthy =
gateway	hook periodic ping	every 5 min	gateway is running
whatsapp	hook — last message:received age	every 5 min	received event in last 30 min
cron-sync	sync script	every 15 min	last sync succeeded
disk	sync script or hook	every 15 min	<90% used

Implementation options

A — Hook periodic heartbeat (preferred)

Add a setInterval in handler.ts that calls sendHealth("gateway", "ok", "Heartbeat") every 5 minutes. Also track last message:received timestamp and send a warning if >30 min silent.

B — Sync script health ping (quick win)

Add a POST /api/v1/ingest/health call at the end of sync.py after each successful sync run. Already runs every 15 min.

Related

• examples/openclaw-hook/handler.ts — needs setInterval heartbeat
• examples/openclaw-cron-sync/sync.py — can add health ping as quick win