feat(core,ui): support Gemini 3.1 Pro Preview and active model filtering (#125)

* feat(core,ui): support Gemini 3.1 Pro Preview and active model filtering

* fix(core,ui): use optional chaining for config methods to support mocks

* fix(core): clear stale authType in refreshAuth to avoid incorrect model resolution

* do not show gemini 3.1 model when users do not have access to gemini 3.1 in stats

packages/cli/src/ui/hooks/useQuotaAndFallback.ts

@@ -14,9 +14,8 @@ import {
   TerminalQuotaError,
   ModelNotFoundError,
   type UserTierId,
-  PREVIEW_GEMINI_MODEL,
-  DEFAULT_GEMINI_MODEL,
   VALID_GEMINI_MODELS,
+  isProModel,
 } from '@google/gemini-cli-core';
 import { useCallback, useEffect, useRef, useState } from 'react';
 import { type UseHistoryManagerReturn } from './useHistoryManager.js';
@@ -67,11 +66,9 @@ export function useQuotaAndFallback({
       let message: string;
       let isTerminalQuotaError = false;
       let isModelNotFoundError = false;
-      const usageLimitReachedModel =
-        failedModel === DEFAULT_GEMINI_MODEL ||
-        failedModel === PREVIEW_GEMINI_MODEL
-          ? 'all Pro models'
-          : failedModel;
+      const usageLimitReachedModel = isProModel(failedModel)
+        ? 'all Pro models'
+        : failedModel;
       if (error instanceof TerminalQuotaError) {
         isTerminalQuotaError = true;
         // Common part of the message for both tiers