Backend issues short-lived guildAccessToken (TTL=900s). The previous
`auth: { token: tok }` shape captured the JWT once in connectAgent's
closure: after socket.io's auto-reconnect the backend kept getting the
same expired JWT and silently rejected the handshake at the application
layer (RealtimeGateway logs 'socket rejected: <id>'). The client's
'connect' event still fired (TCP succeeded) so the plugin happily ran
the channel-resync, emitted join_channel into the void, and logged
'joined N channel(s)' while the backend was actually broadcasting
message.created to a room with zero subscribers. End-user symptom:
DMs/group messages to agents silently dropped 15 min after gateway
start, with no error anywhere on the agent side.
Switch to the callback form, which socket.io re-evaluates on every
(re)connect — same call site we already use for the HTTP path via
freshGuildToken/tokenCache.
Verified in sim (commit 2acb084 + this patch):
1. Connect new DM channel + post msg -> dispatch + reply ✓
2. `docker restart fabric-backend-guild` to force socket disconnect
3. Plugin reconnects automatically and logs
'fabric: agent recruiter joined 12 channel(s) on sim-guild-1' ✓
(without the fix this reconnect was silently rejected; sim used to
log 'WARN socket rejected: <id>' on the guild backend)
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
hzhang
7dc70522d1