feat: implement Codex OAuth flow with loopback callback server and management UI

- Add localCallbackServer for handling OAuth callback requests.
- Implement service functions for managing OAuth sessions and accounts.
- Create CodexAdapter for platform-specific interactions.
- Develop OAuthManagement page for managing OAuth connections and providers.
- Add tests for localCallbackServer and OAuthManagement components.

src/server/services/platforms/codex.ts

@@ -0,0 +1,34 @@
+import { BasePlatformAdapter, type BalanceInfo, type CheckinResult, type UserInfo } from './base.js';
+
+function normalizeBaseUrl(baseUrl: string): string {
+  return (baseUrl || '').replace(/\/+$/, '');
+}
+
+export class CodexAdapter extends BasePlatformAdapter {
+  readonly platformName = 'codex';
+
+  async detect(url: string): Promise<boolean> {
+    const normalized = normalizeBaseUrl(url).toLowerCase();
+    return normalized.includes('chatgpt.com/backend-api/codex');
+  }
+
+  override async login(_baseUrl: string, _username: string, _password: string) {
+    return { success: false as const, message: 'codex oauth login is managed via OAuth flow' };
+  }
+
+  override async getUserInfo(_baseUrl: string, _accessToken: string): Promise<UserInfo | null> {
+    return null;
+  }
+
+  async checkin(_baseUrl: string, _accessToken: string): Promise<CheckinResult> {
+    return { success: false, message: 'codex oauth connections do not support checkin' };
+  }
+
+  async getBalance(_baseUrl: string, _accessToken: string): Promise<BalanceInfo> {
+    return { balance: 0, used: 0, quota: 0 };
+  }
+
+  async getModels(_baseUrl: string, _token: string): Promise<string[]> {
+    return [];
+  }
+}

src/server/services/platforms/index.test.ts

@@ -58,6 +58,11 @@ describe('getAdapter platform aliases', () => {
     expect(getAdapter('gemini')?.platformName).toBe('gemini');
   });
 
+  it('supports dedicated codex adapter and aliases', () => {
+    expect(getAdapter('codex')?.platformName).toBe('codex');
+    expect(getAdapter('chatgpt-codex')?.platformName).toBe('codex');
+  });
+
   it('detects anyrouter URL before generic new-api adapter', async () => {
     const adapter = await detectPlatform('https://anyrouter.top');
     expect(adapter?.platformName).toBe('anyrouter');

src/server/services/platforms/index.ts

@@ -7,6 +7,7 @@ import { OneHubAdapter } from './oneHub.js';
 import { DoneHubAdapter } from './doneHub.js';
 import { Sub2ApiAdapter } from './sub2api.js';
 import { OpenAiAdapter } from './openai.js';
+import { CodexAdapter } from './codex.js';
 import { ClaudeAdapter } from './claude.js';
 import { GeminiAdapter } from './gemini.js';
 import { CliProxyApiAdapter } from './cliproxyapi.js';
@@ -15,6 +16,7 @@ import { detectPlatformByTitle } from './titleHint.js';
 const adapters: PlatformAdapter[] = [
   // Specific forks before generic adapters for better auto-detection.
   new OpenAiAdapter(),
+  new CodexAdapter(),
   new ClaudeAdapter(),
   new GeminiAdapter(),
   new CliProxyApiAdapter(),
@@ -49,6 +51,9 @@ const platformAliases: Record<string, string> = {
   sub2api: 'sub2api',
   // Official upstream APIs
   openai: 'openai',
+  codex: 'codex',
+  'chatgpt-codex': 'codex',
+  'chatgpt codex': 'codex',
   anthropic: 'claude',
   claude: 'claude',
   gemini: 'gemini',
@@ -83,6 +88,7 @@ function detectPlatformByUrlHint(url: string): string | undefined {
 
   // Official upstream endpoints.
   if (normalized.includes('api.openai.com')) return 'openai';
+  if (normalized.includes('chatgpt.com/backend-api/codex')) return 'codex';
   if (normalized.includes('api.anthropic.com') || normalized.includes('anthropic.com/v1')) return 'claude';
   if (
     normalized.includes('generativelanguage.googleapis.com')