- Add notifyParentSession() to send message to parent session via prompt()
- Agent receives completion notification immediately, not waiting for next chat.message
- Includes task ID, description, duration, tool calls in notification
🤖 GENERATED WITH ASSISTANCE OF [OhMyOpenCode](https://github.com/code-yeongyu/oh-my-opencode)
- Replace unreliable event-based tracking with 2-second polling
- Use SDK session.get() to detect completion (status === idle)
- Use SDK session.messages() to count tool_use parts for progress
- Auto-start polling on launch, auto-stop when no running tasks
- Resume polling on restore if running tasks exist
Fixes: Child session events not reaching plugin event handler
🤖 GENERATED WITH ASSISTANCE OF [OhMyOpenCode](https://github.com/code-yeongyu/oh-my-opencode)
