v3.9.0 - Q&A Enhancements & Breakout Outline Integration

- `!question <hash>` - Expanded question view with full context
- `!clarify <hash> <text>` - Add clarifications/elaborations to questions
- `!accept <hash> <answer_id>` - Accept answer as solution (DMs answerer)
- `!reject <hash> <answer_id> <reason>` - Reject with reason (DMs answerer)
- Full question text in `!questions` list (no truncation)
- Cross-group question lookup for expanded view

- Outline document auto-created when breakout starts
- Public share link in welcome message
- Outline link in late joiner catch-up DM
- Document updated with full summary when session ends

- New tables: q_and_a_clarifications, q_and_a_answer_responses
- New columns on q_and_a_answers: status, rejection_reason, answerer_uuid
- New columns on breakout_rooms: outline_document_id, outline_url