fix: faster WebSocket reconnect on iOS PWA

- connection timeout after 4s (vs OS TCP default ~75s)
- visibilitychange listener: reconnect immediately when app resumes

extensions/remote-control/html.ts

@@ -607,17 +607,26 @@ export function buildHTML(nonce: string): string {
     }
   }
 
-  var ws, timer;
+  var ws, timer, connectTimer;
   function connect() {
+    if (ws && (ws.readyState === 0 || ws.readyState === 1)) return;
+    clearTimeout(connectTimer);
     var wsProtocol = location.protocol === "https:" ? "wss:" : "ws:";
     ws = new WebSocket(wsProtocol + "//" + location.host + "/ws");
 
+    // If not connected within 4s, close and retry immediately
+    connectTimer = setTimeout(function () {
+      if (ws && ws.readyState !== 1) { ws.close(); }
+    }, 4000);
+
     ws.onopen = function () {
       clearTimeout(timer);
+      clearTimeout(connectTimer);
       updateStatus(true);
     };
 
     ws.onclose = function () {
+      clearTimeout(connectTimer);
       updateStatus(false);
       clearTimeout(timer);
       timer = setTimeout(connect, 2000);
@@ -717,6 +726,14 @@ export function buildHTML(nonce: string): string {
   });
 
   connect();
+
+  // Reconnect immediately when app comes back to foreground (e.g. iOS PWA resume)
+  document.addEventListener("visibilitychange", function () {
+    if (document.visibilityState === "visible") {
+      clearTimeout(timer);
+      if (!ws || ws.readyState === 2 || ws.readyState === 3) connect();
+    }
+  });
 })();
 </script>
 </body>