- New task_comments table (separate from progress notes)
- Backend: GET/POST/DELETE /api/tasks/:id/comments with session + bearer auth
- TaskComments component on TaskPage (full-page view) with markdown support,
author avatars, delete own comments, 30s polling
- CompactComments in TaskDetailPanel (side panel) with last 3 + expand
- Comment API functions in frontend lib/api.ts