Killed "active" session dependency:

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

.gitignore

@@ -78,3 +78,7 @@ alembic/versions/*.pyc
 .DS_Store
 .AppleDouble
 .LSOverride
+
+/docs
+/data
+/#recycle