fix(core): remove OAuth check from handleFallback and clean up stray file (#21962)

packages/core/src/fallback/handler.test.ts

@@ -59,7 +59,6 @@ vi.mock('../utils/debugLogger.js', () => ({
 const MOCK_PRO_MODEL = DEFAULT_GEMINI_MODEL;
 const FALLBACK_MODEL = DEFAULT_GEMINI_FLASH_MODEL;
 const AUTH_OAUTH = AuthType.LOGIN_WITH_GOOGLE;
-const AUTH_API_KEY = AuthType.USE_GEMINI;
 
 const createMockConfig = (overrides: Partial<Config> = {}): Config =>
   ({
@@ -129,16 +128,6 @@ describe('handleFallback', () => {
       );
     });
 
-    it('should return null immediately if authType is not OAuth', async () => {
-      const result = await handleFallback(
-        policyConfig,
-        MOCK_PRO_MODEL,
-        AUTH_API_KEY,
-      );
-      expect(result).toBeNull();
-      expect(policyHandler).not.toHaveBeenCalled();
-    });
-
     it('uses availability selection with correct candidates when enabled', async () => {
       // Direct mock manipulation since it's already a vi.fn()
       vi.mocked(policyConfig.getModel).mockReturnValue(

packages/core/src/fallback/handler.ts

@@ -5,7 +5,6 @@
  */
 
 import type { Config } from '../config/config.js';
-import { AuthType } from '../core/contentGenerator.js';
 import {
   openBrowserSecurely,
   shouldLaunchBrowser,
@@ -29,10 +28,6 @@ export async function handleFallback(
   authType?: string,
   error?: unknown,
 ): Promise<string | boolean | null> {
-  if (authType !== AuthType.LOGIN_WITH_GOOGLE) {
-    return null;
-  }
-
   const chain = resolvePolicyChain(config);
   const { failedPolicy, candidates } = buildFallbackPolicyContext(
     chain,