Merge remote-tracking branch 'origin/main' into maestoso

The visibility recovery only reconnected the catalog and daemon-link
sockets. Per-pane attach and structured WebSockets relied on backoff
timers that Android suspends alongside the sockets, leaving the
terminal disconnected after backgrounding.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

web/src/components/structured/useStructuredSession.ts

@@ -196,12 +196,24 @@ export function useStructuredSession(
       connect();
     };
 
+    // Mobile browsers suspend timers and silently kill WebSockets in the
+    // background. Kick a fresh connect when the page becomes visible again.
+    const onVisibility = () => {
+      if (document.visibilityState !== "visible" || disposed) return;
+      if (socket && (socket.readyState === WebSocket.OPEN || socket.readyState === WebSocket.CONNECTING)) return;
+      cancelTimer();
+      setStatus("reconnecting");
+      connect();
+    };
+    document.addEventListener("visibilitychange", onVisibility);
+
     setStatus("connecting");
     connect();
 
     return () => {
       disposed = true;
       reconnectRef.current = () => {};
+      document.removeEventListener("visibilitychange", onVisibility);
       cancelTimer();
       closeSocket();
     };

web/src/components/terminal/TerminalPane.tsx

@@ -302,6 +302,24 @@ export const TerminalPane = forwardRef<TerminalPaneHandle, TerminalPaneProps>(
       ta?.addEventListener("focus", onTaFocus);
       ta?.addEventListener("blur", onTaBlur);
 
+      // Mobile browsers (Android especially) suspend timers and silently kill
+      // WebSockets when the app goes to background. The backoff timer set by
+      // onclose is frozen too, so recovery stalls until visibility returns. Kick
+      // a fresh connect immediately when the page becomes visible again.
+      const onVisibility = () => {
+        if (document.visibilityState !== "visible" || disposed) return;
+        if (ws.readyState === WebSocket.OPEN || ws.readyState === WebSocket.CONNECTING) return;
+        // Cancel any pending backoff — we're reconnecting right now.
+        if (reconnectTimer !== null) {
+          window.clearTimeout(reconnectTimer);
+          reconnectTimer = null;
+        }
+        reconnectMs = INITIAL_RECONNECT_MS;
+        onStatusChange?.("reconnecting");
+        connect();
+      };
+      document.addEventListener("visibilitychange", onVisibility);
+
       window.addEventListener("resize", onResize);
       const visual = window.visualViewport ?? null;
       visual?.addEventListener("resize", onResize);
@@ -326,6 +344,7 @@ export const TerminalPane = forwardRef<TerminalPaneHandle, TerminalPaneProps>(
           reconnectTimer = null;
         }
         ro.disconnect();
+        document.removeEventListener("visibilitychange", onVisibility);
         window.removeEventListener("resize", onResize);
         visual?.removeEventListener("resize", onResize);
         ta?.removeEventListener("focus", onTaFocus);