chore(core): remove redundant isModelAvailabilityServiceEnabled toggle and clean up dead code (#15207)

packages/core/src/availability/policyHelpers.test.ts

@@ -119,7 +119,6 @@ describe('policyHelpers', () => {
       overrides: Partial<Config> = {},
     ): Config => {
       const defaults = {
-        isModelAvailabilityServiceEnabled: () => true,
         getModelAvailabilityService: () => mockAvailabilityService,
         setActiveModel: vi.fn(),
         modelConfigService: mockModelConfigService,
@@ -131,15 +130,6 @@ describe('policyHelpers', () => {
       vi.clearAllMocks();
     });
 
-    it('returns requested model if availability service is disabled', () => {
-      const config = createExtendedMockConfig({
-        isModelAvailabilityServiceEnabled: () => false,
-      });
-      const result = applyModelSelection(config, 'gemini-pro');
-      expect(result.model).toBe('gemini-pro');
-      expect(config.setActiveModel).not.toHaveBeenCalled();
-    });
-
     it('returns requested model if it is available', () => {
       const config = createExtendedMockConfig();
       mockAvailabilityService.selectFirstAvailable.mockReturnValue({

packages/core/src/availability/policyHelpers.ts

@@ -117,9 +117,6 @@ export function createAvailabilityContextProvider(
   modelGetter: () => string,
 ): () => RetryAvailabilityContext | undefined {
   return () => {
-    if (!config.isModelAvailabilityServiceEnabled()) {
-      return undefined;
-    }
     const service = config.getModelAvailabilityService();
     const currentModel = modelGetter();
 
@@ -138,11 +135,7 @@ export function createAvailabilityContextProvider(
 export function selectModelForAvailability(
   config: Config,
   requestedModel: string,
-): ModelSelectionResult | undefined {
-  if (!config.isModelAvailabilityServiceEnabled()) {
-    return undefined;
-  }
-
+): ModelSelectionResult {
   const chain = resolvePolicyChain(config, requestedModel);
   const selection = config
     .getModelAvailabilityService()