Added debug logging to federation signal path. Fixed the announce/recv
flow: outbound link's announce_task sends FederationRoomJoin, peer's
inbound signal_task receives it and creates virtual participant.
Tested: two relays on localhost with mutual TOML config, client A
sends tone via relay A, client B records via relay B — audio received
through federation (0.1s/RMS 7291/PASS).
Room announcement delay is ~1s (poll interval). The full pipeline:
client join → room created → announce_task detects → sends signal →
peer receives → creates virtual participant → SFU loop forwards
media via room-hash-tagged datagrams → peer demuxes → local delivery.
Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>