fix: stop nullifying wsConnection prematurely in close/terminate

fix: stop nullifying wsConnection prematurely in close/terminate

closeWSConnection() and terminateWSConnection() set wsConnection to null
immediately after calling close()/terminate(), but the 'close' event
fires asynchronously afterward. The onClose handler then emitted an
'updated' event with wsState undefined (since wsConnection was null),
causing the UI to display 'ws unknown' instead of 'ws closed'.

Remove the null assignments — the stale WebSocket reference is harmless
(overwritten by the next openWSConnection call) and allows onClose to
read the correct readyState (CLOSED=3) when emitting state updates.