1. roboco/mcp/schemas/__init__.py:
- SendMessageInput.task_id → required
- AskQuestionInput.task_id → required
- ReportBlockerInput.task_id → required
2. roboco/mcp/message_server.py:
- Removed _get_active_session() entirely (dead code)
- Simplified _handle_message_send() - no fallback, just uses task's linked session
- Updated tool signatures for roboco_ask_question and roboco_report_blocker
3. roboco/api/routes/tasks.py (earlier fix):
- Added subtask validation before parent completion
New behavior:
- All messages MUST have task_id
- Task's linked session is the only source of truth
- No session? → Clear error: "Cell PM must create one"
- No more "active" status guessing