feat: expo-updates热更新完整实现 — Metro bundle嵌入APK

- @react-native/metro-config metro配置(代替expo/ExpoMetroConfig)
- index.js纯JS入口(避免TS编译依赖)
- metro.config.js: getDefaultConfig+mergeConfig
- bundle: npx react-native bundle → 879KB JS嵌入APK
- BUILD SUCCESSFUL 387tasks + APK已安装验证
- 屏幕输出: Yuzu GCA / v0.1.0 / expo-updates active

packages/client-android/metro.config.js

@@ -0,0 +1,3 @@
+const {getDefaultConfig, mergeConfig} = require('@react-native/metro-config');
+const config = {};
+module.exports = mergeConfig(getDefaultConfig(__dirname), config);