feat: silent wechat login, marketing tab optimization, admin page foundation

- Add silent WeChat login for MP/browser environments
- Fix Python 3.6 compatibility (remove typing.Annotated usage)
- Marketing page: tab-based content generation with category support
- Translate page: add auto-detect language default
- Homepage: add TTS playback, announcement ticker, remove redundant quick-actions
- Fix FAB button overlap with custom tabbar on customers/quotation pages
- Make openai/anthropic imports lazy for Python 3.6 compat

uni-app/src/utils/api.js

@@ -61,6 +61,7 @@ export const authApi = {
   register: (phone, password, username) => request('/auth/register', 'POST', { phone, password, username }),
   getUserInfo: () => request('/auth/me'),
   wechatLogin: (code) => request('/auth/wechat-login', 'POST', { code }),
+  wechatConfig: () => request('/auth/wechat/config'),
   guestLogin: () => requestWithoutAuth('/auth/login/guest', 'POST'),
 }