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/metro.config.js

@@ -3,29 +3,6 @@ const { withNativeWind } = require('nativewind/metro');
 
 const config = getDefaultConfig(__dirname);
 
-// --- Web: Required for expo-sqlite ---
-// expo-sqlite on web uses SQLite compiled to WASM; Metro must treat .wasm as an asset.
-if (!config.resolver.assetExts.includes('wasm')) {
-  config.resolver.assetExts.push('wasm');
-}
-
-// --- Web: Required for expo-sqlite ---
-// SharedArrayBuffer (used by SQLite WASM) requires COEP/COOP headers.
-// Dev server: set here. Production: set via app.config.js expo-router headers.
-config.server = config.server ?? {};
-const existingEnhanceMiddleware = config.server.enhanceMiddleware;
-config.server.enhanceMiddleware = (middleware, server) => {
-  const nextMiddleware = existingEnhanceMiddleware
-    ? existingEnhanceMiddleware(middleware, server)
-    : middleware;
-
-  return (req, res, next) => {
-    res.setHeader('Cross-Origin-Embedder-Policy', 'credentialless');
-    res.setHeader('Cross-Origin-Opener-Policy', 'same-origin');
-    return nextMiddleware(req, res, next);
-  };
-};
-
 module.exports = withNativeWind(config, {
   input: './src/global.css',
   inlineRem: 16,