Implement multi-phase improvement to respawn controller's idle detection:
Phase 1 - Stop Hook Detection:
- Add signalStopHook() method - definitive signal when Claude finishes
- 3s confirmation timer to handle race conditions
- Skip AI check when hook received (100% confidence)
Phase 2 - idle_prompt Detection:
- Add signalIdlePrompt() method - fires after 60s+ of idle
- Immediately confirms idle (no confirmation timer needed)
Phase 3 - Transcript File Monitoring:
- New TranscriptWatcher class watches session JSONL files
- Detects: completion, tool execution, plan mode, errors
- Signals respawn controller for supporting detection
Web UI Updates:
- Hook indicator with purple styling and pulse animation
- Shows "Stop hook received" or "idle_prompt hook received"
- 100% confidence displayed with hook-confirmed style
This significantly improves idle detection reliability by using
definitive signals from Claude Code rather than parsing terminal output.
Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>