Root causes:
- Mock readline (EventEmitter) lacked .close() method, causing TypeError
that blocked extractDescriptionFromFile's Promise from ever resolving
- Mock stream lacked .destroy() method (same issue after .close() fix)
- Entry-processing tests shared one readline mock between description
extraction and tailing — events emitted before tailFile started were lost
- Liveness checker marked agents as 'completed' instead of 'idle' because
fixed stat timestamps became stale after fake timer advancement
Fixes:
- Add createMockRl() helper with .close() method
- Use { destroy: vi.fn() } for stream mocks
- Use mockReturnValueOnce() for two-readline pattern in 7 entry tests
- Use mockImplementation() for dynamic stat timestamps
Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>
- Add 100ms debounce for new file detection to allow content to be written
- Add subagent:updated event for retroactive description updates
- Extract description in processEntry when first user message is processed
- Add extractDescriptionFromFile helper with retry in file change handler
- Update SubagentTranscriptEntry.content type to support string | array
- Add test coverage for subagent:updated event
Fixes 43% failure rate where subagents displayed raw IDs instead of descriptions
due to race condition when files were discovered before first line was written.
Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>