build(android): 生成原生Android工程 — Android Studio直接构建

- android/: 完整Gradle工程(build.gradle/settings/AndroidManifest/Activity/Application)
- PackageInstallerModule: 重写为ReactContextBaseJavaModule (bare RN, 移除Expo依赖)
- 新增sha256File原生方法, installApk改为Promise异步
- 移除旧的modules/ (Expo Module → bare React Native)
- 添加eas.json (备用云端构建)

packages/client-android/eas.json

@@ -0,0 +1,23 @@
+{
+  "cli": {
+    "version": ">= 14.0.0"
+  },
+  "build": {
+    "preview": {
+      "android": {
+        "buildType": "apk",
+        "env": {
+          "APP_VERSION": "0.1.0"
+        }
+      }
+    },
+    "production": {
+      "android": {
+        "buildType": "apk"
+      }
+    }
+  },
+  "submit": {
+    "production": {}
+  }
+}