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>