ax(node): replace prose comment with usage example on handleWSUpgrade

The comment "handleWSUpgrade handles incoming WebSocket connections" restated
the function signature without adding information. Replaced with a concrete
call-site example showing how the method is wired in via Start().

Co-Authored-By: Charon <charon@lethean.io>

pkg/node/transport.go

@@ -411,7 +411,7 @@ func (t *Transport) GetConnection(peerID string) *PeerConnection {
 	return t.conns[peerID]
 }
 
-// handleWSUpgrade handles incoming WebSocket connections.
+// mux.HandleFunc(cfg.WSPath, t.handleWSUpgrade) // registered in NewTransport via Start()
 func (t *Transport) handleWSUpgrade(w http.ResponseWriter, r *http.Request) {
 	// Enforce MaxConns limit (including pending connections during handshake)
 	t.mutex.RLock()