fix: stabilize cloud computer use mcp

server/modules/computer-use/computer-use.service.ts

@@ -465,6 +465,7 @@ export const computerUseService = {
       await this.registerAgentMcp();
     } else {
       await this.unregisterAgentMcp();
+      desktopAgentRelay.disconnectAll('Computer Use was disabled in this environment.');
       stopSessions('settings:disabled', 'Computer Use was disabled in settings.');
     }
     return next;
@@ -909,6 +910,7 @@ export const computerUseService = {
 
 // Drive cloud MCP exposure + session teardown off desktop-agent connectivity.
 desktopAgentRelay.setHooks({
+  canAcceptConnection: () => getRuntime() === 'cloud' && readSettings().enabled,
   onFirstConnect: () => computerUseService.onDesktopAgentConnected(),
   onLastDisconnect: () => computerUseService.onDesktopAgentDisconnected(),
 });

server/modules/computer-use/desktop-agent-relay.service.ts

@@ -18,6 +18,7 @@ type ConnectedAgent = {
 };
 
 type RelayLifecycleHooks = {
+  canAcceptConnection?: () => boolean;
   onFirstConnect?: () => void | Promise<void>;
   onLastDisconnect?: () => void | Promise<void>;
 };
@@ -54,15 +55,25 @@ export const desktopAgentRelay = {
     hooks = next;
   },
 
-  register(ws: WebSocket, label = 'desktop-agent'): void {
+  register(ws: WebSocket, label = 'desktop-agent'): boolean {
+    if (hooks.canAcceptConnection && !hooks.canAcceptConnection()) {
+      console.log(`[DesktopAgent] Rejected (${label}); Computer Use is disabled.`);
+      try {
+        ws.close(1008, 'Computer Use is disabled in this environment.');
+      } catch {
+        // ignore close failures
+      }
+      return false;
+    }
+
     const wasEmpty = pickAgent() === undefined;
     agents.set(ws, { ws, label, registeredAt: new Date().toISOString() });
     console.log(`[DesktopAgent] Registered (${label}); ${agents.size} connected.`);
 
     ws.on('close', () => {
-      agents.delete(ws);
+      const wasRegistered = agents.delete(ws);
       console.log(`[DesktopAgent] Disconnected (${label}); ${agents.size} remain.`);
-      if (pickAgent() === undefined) {
+      if (wasRegistered && pickAgent() === undefined) {
         rejectAllPending('Desktop agent disconnected.');
         void hooks.onLastDisconnect?.();
       }
@@ -71,6 +82,24 @@ export const desktopAgentRelay = {
     if (wasEmpty) {
       void hooks.onFirstConnect?.();
     }
+    return true;
+  },
+
+  disconnectAll(reason = 'Desktop agent disconnected.'): void {
+    const hadAgent = pickAgent() !== undefined;
+    const sockets = [...agents.keys()];
+    agents.clear();
+    for (const ws of sockets) {
+      try {
+        ws.close(1008, reason);
+      } catch {
+        // ignore close failures
+      }
+    }
+    rejectAllPending(reason);
+    if (hadAgent) {
+      void hooks.onLastDisconnect?.();
+    }
   },
 
   /** Resolves a pending relay call with the desktop agent's reply. */