Added warn-level log in handle_datagram when a federation
datagram arrives but no matching local room is found. Prints:
- room_hash (8-byte tag from the datagram)
- active_rooms (all rooms the relay currently has)
- seq + peer label
This diagnoses the cross-relay recv_fr=0 issue: if media IS
arriving from the peer relay but the room hash doesn't match any
active room, the log tells us exactly what hash is expected vs
what rooms exist locally. If no datagram log fires at all, the
issue is upstream (peer relay not forwarding, federation link
down, etc.).
Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>
026940d492