Pass parentTools from session-tools-store through the background task
lifecycle (launch → task → notify) so that when notifyParentSession
sends promptAsync, the original tool restrictions (e.g., question: false)
are preserved. This prevents the Question tool from re-enabling after
call_omo_agent background tasks complete.
When delegate-task resumes a session via session_id, the response
task_metadata now includes a subagent field identifying which agent
was running in the resumed session. This allows the parent agent to
know what type of subagent it is continuing.
- sync-continuation: uses resumeAgent extracted from session messages
- background-continuation: uses task.agent from BackgroundTask object
- Gracefully omits subagent when agent info is unavailable
