When the engine boots, if an agent has the new
runMissedHeartbeatOnStartup flag enabled and lastHeartbeatAt is older
than its interval, fire one catch-up heartbeat through the existing
executeHeartbeat path. Default is off, so existing agents are
unchanged. Toggle exposed in the agent's Heartbeat Settings tab.
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>