fix(local-agent): harden pair/reconnect auth and credential rotation

Consume pairing tokens only after successful WS registration, revoke
prior reconnect credentials on re-pair, emit reconnect.ok, and wait
for server ack before marking the extension connected.

Co-authored-by: Cursor <cursoragent@cursor.com>

src/connectLocalController.ts

@@ -30,6 +30,10 @@ export class ConnectLocalController {
     resolve: (value: LocalAgentServerMessage & { type: 'pair.ok' }) => void;
     reject: (error: Error) => void;
   }> = [];
+  private reconnectWaiters: Array<{
+    resolve: (value: LocalAgentServerMessage & { type: 'reconnect.ok' }) => void;
+    reject: (error: Error) => void;
+  }> = [];
 
   constructor(deps: ConnectLocalControllerDeps) {
     this.pi = deps.pi;
@@ -150,14 +154,29 @@ export class ConnectLocalController {
     }
     try {
       await this.ensureClient(stored.wsUrl || this.wsUrl);
+      const reconnectOk = await new Promise<LocalAgentServerMessage & { type: 'reconnect.ok' }>((resolve, reject) => {
+        const timeout = setTimeout(() => reject(new Error('Reconnect timed out')), 30_000);
+        this.reconnectWaiters.push({
+          resolve: (value) => {
+            clearTimeout(timeout);
+            resolve(value);
+          },
+          reject: (error) => {
+            clearTimeout(timeout);
+            reject(error);
+          },
+        });
         this.client!.send({
           type: 'reconnect',
           credential: stored.credential,
           projectName: stored.projectName,
           connectionEpoch: this.connectionEpoch,
         });
-      this.projectName = stored.projectName;
+      });
+      this.projectName = reconnectOk.projectName;
+      this.connectionEpoch = reconnectOk.connectionEpoch;
     } catch {
+      this.projectName = undefined;
       /* extension must not block Pi; reconnect can be retried manually */
     }
   }
@@ -190,9 +209,19 @@ export class ConnectLocalController {
       waiter?.resolve(message);
       return;
     }
+    if (message.type === 'reconnect.ok') {
+      const waiter = this.reconnectWaiters.shift();
+      waiter?.resolve(message);
+      return;
+    }
     if (message.type === 'error') {
-      const waiter = this.pairWaiters.shift();
-      waiter?.reject(new Error(message.message));
+      const pairWaiter = this.pairWaiters.shift();
+      if (pairWaiter) {
+        pairWaiter.reject(new Error(message.message));
+        return;
+      }
+      const reconnectWaiter = this.reconnectWaiters.shift();
+      reconnectWaiter?.reject(new Error(message.message));
       return;
     }
     if (message.type === 'task.dispatch') {