Adds notification system for full visibility into the DevClaw pipeline:
Events and targets:
- workerStart: Posted to project group when worker spawns/resumes
- workerComplete: Posted to project group when DEV done/QA pass/fail/refine
- heartbeat: Posted to orchestrator DM with tick summary
Implementation:
- New lib/notify.ts module with buildMessage() and sendMessage()
- Integrated into task_pickup, task_complete, and heartbeat_tick
- Uses OpenClaw gateway to invoke message tool
Configuration (optional):
- orchestratorDm: Chat ID for heartbeat notifications
- notifications.heartbeatDm: Enable/disable heartbeat DM (default: true)
- notifications.workerStart: Enable/disable start notifications (default: true)
- notifications.workerComplete: Enable/disable completion notifications (default: true)
Notifications fail silently (logged but don't break main flow).
