feat(zed-integration): Use default model routing for Zed integration (#13398)

Co-authored-by: Shreya Keshive <shreyakeshive@google.com>

packages/cli/src/zed-integration/zedIntegration.ts

@@ -27,11 +27,9 @@ import {
   DiscoveredMCPTool,
   StreamEventType,
   ToolCallEvent,
-  DEFAULT_GEMINI_MODEL,
-  DEFAULT_GEMINI_MODEL_AUTO,
-  DEFAULT_GEMINI_FLASH_MODEL,
   debugLogger,
   ReadManyFilesTool,
+  getEffectiveModel,
 } from '@google/gemini-cli-core';
 import * as acp from './acp.js';
 import { AcpFileSystemService } from './fileSystemService.js';
@@ -47,19 +45,6 @@ import { randomUUID } from 'node:crypto';
 import type { CliArgs } from '../config/config.js';
 import { loadCliConfig } from '../config/config.js';
 
-/**
- * Resolves the model to use based on the current configuration.
- *
- * If the model is set to "auto", it will use the flash model if in fallback
- * mode, otherwise it will use the default model.
- */
-export function resolveModel(model: string, isInFallbackMode: boolean): string {
-  if (model === DEFAULT_GEMINI_MODEL_AUTO) {
-    return isInFallbackMode ? DEFAULT_GEMINI_FLASH_MODEL : DEFAULT_GEMINI_MODEL;
-  }
-  return model;
-}
-
 export async function runZedIntegration(
   config: Config,
   settings: LoadedSettings,
@@ -264,9 +249,10 @@ class Session {
       const functionCalls: FunctionCall[] = [];
 
       try {
-        const model = resolveModel(
+        const model = getEffectiveModel(
-          this.config.getModel(),
           this.config.isInFallbackMode(),
+          this.config.getModel(),
+          this.config.getPreviewFeatures(),
         );
         const responseStream = await chat.sendMessageStream(
           { model },