feat(app-expo): 聊天键盘与列表滚动改用 keyboard-controller，并收敛 Web 构建配置

聊天（conversation/[id]）
- 根布局挂载 KeyboardProvider，会话页使用 react-native-keyboard-controller 的
  KeyboardAvoidingView（padding + 仅文字模式 enabled），替代手写 keyboardLift 与
  RN KeyboardAvoidingView 分端逻辑，改善 Android 键盘遮挡与布局一致性。
- 键盘：keyboardDidShow 后 scrollToEnd；iOS 用 keyboardWillShow 提前更新键盘可见状态；
  收起使用 WillHide/DidHide；监听在 effect 中统一移除。
- 输入框高度：ChatInputBar 通过 onInputDisplayHeightChange 在 inputDisplayHeight 变化时
  触发滚到底；保留底部容器 onLayout 以覆盖连接提示与整块高度变化。

配置与构建
- app.config：移除 web 块与 expo-sqlite Web 所需的 COEP/COOP headers；expo-router 插件
  改为无参；Android 显式 softwareKeyboardLayoutMode: resize。
- metro.config：移除 wasm 资源与 COOP/COOP dev server
OC

app-expo/README.md

@@ -46,11 +46,11 @@ This command will move the starter code to the **app-example** directory and cre
 To learn more about developing your project with Expo, look at the following resources:
 
 - [Expo documentation](https://docs.expo.dev/): Learn fundamentals, or go into advanced topics with our [guides](https://docs.expo.dev/guides).
-- [Learn Expo tutorial](https://docs.expo.dev/tutorial/introduction/): Follow a step-by-step tutorial where you'll create a project that runs on Android, iOS, and the web.
+- [Learn Expo tutorial](https://docs.expo.dev/tutorial/introduction/): Follow a step-by-step tutorial where you'll create a project that runs on Android and iOS.
 
 ## Join the community
 
-Join our community of developers creating universal apps.
+Join our community of developers creating apps with Expo.
 
 - [Expo on GitHub](https://github.com/expo/expo): View our open source platform and contribute.
 - [Discord community](https://chat.expo.dev): Chat with Expo users and ask questions.