On-air dest hashes are one byte, so a companion and a room-server (or
repeater) identity can share one. The login and text dispatch used
`if dest_hash in companion_bridges: ... elif login_helper/text_helper`,
so a companion silently shadowed a same-hash room server: its login
never reached the room-server handler and failed with Invalid HMAC
(e.g. Lake Stevens pubkey f55d.. / hash 0xf5 colliding with a companion).
Offer the packet to both handlers when both are registered at the hash;
decryption disambiguates — the key owner replies, the other fails HMAC
and no-ops. Non-colliding paths are unchanged. Applied to both the
LoginServerHandler and TextMessageHandler branches.
Adds regression tests covering collision (both invoked), companion-only
(server helper skipped), and server-without-companion for each path.
agessaman
4a055be8df