fix(acp): update auth handshake to spec (#19725)

packages/core/src/code_assist/oauth2.test.ts

@@ -95,6 +95,7 @@ const mockConfig = {
   getNoBrowser: () => false,
   getProxy: () => 'http://test.proxy.com:8080',
   isBrowserLaunchSuppressed: () => false,
+  getExperimentalZedIntegration: () => false,
 } as unknown as Config;
 
 // Mock fetch globally

packages/core/src/code_assist/oauth2.ts

@@ -271,9 +271,12 @@ async function initOauthClient(
 
     await triggerPostAuthCallbacks(client.credentials);
   } else {
-    const userConsent = await getConsentForOauth('');
-    if (!userConsent) {
-      throw new FatalCancellationError('Authentication cancelled by user.');
+    // In Zed integration, we skip the interactive consent and directly open the browser
+    if (!config.getExperimentalZedIntegration()) {
+      const userConsent = await getConsentForOauth('');
+      if (!userConsent) {
+        throw new FatalCancellationError('Authentication cancelled by user.');
+      }
     }
 
     const webLogin = await authWithWeb(client);