Feishu adapter's disconnect() cancelled WSS-thread tasks but never
called the lark_oapi client's _disconnect() coroutine, so no
WebSocket CLOSE frame was sent. Feishu's server kept routing
messages to the stale endpoint for minutes (CLOSE-WAIT timeout),
silencing the channel across every shutdown path — systemd restart,
hermes update, hermes gateway restart, and the --replace takeover
during 'hermes dashboard' invocations.
Schedule ws_client._disconnect() on the WSS thread loop via
run_coroutine_threadsafe with a 5s timeout before the existing
task-cancel + loop-stop sequence. Defensive hasattr guard + broad
except keeps disconnect() resilient if lark_oapi's internals shift.
Fixes#10202