_broadcast_session was missing morning_routine in its payload, so the
TV dashboard's applySnapshot reset the list to [] whenever a session
started or updated via WebSocket. A page refresh was required to
restore the items since only the REST dashboard endpoint included them.
Now queries MorningRoutineItem via child→user_id and adds the list to
every session_update broadcast, matching the dashboard snapshot.
Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>