feat: webview manager and js bridge skeleton

app/src/main/java/top/yeij/hearth/MainActivity.kt

@@ -1,10 +1,13 @@
 package top.yeij.hearth
 
 import android.app.Activity
+import android.content.res.Configuration
 import android.os.Bundle
 import android.util.Log
 import android.view.WindowInsets
 import android.view.WindowInsetsController
+import top.yeij.hearth.webview.JsBridge
+import top.yeij.hearth.webview.WebViewManager
 
 // HOME 桌面 activity，后续 Task 挂载 WebView 与 JsBridge
 // HOME launcher activity; later tasks mount WebView and JsBridge
@@ -18,6 +21,28 @@ class MainActivity : Activity() {
         super.onCreate(savedInstanceState)
         Log.d(TAG, "onCreate: enter immersive mode")
         enterImmersive()
+        setupWebView()
+    }
+
+    // 创建 JsBridge 并挂载 WebView 桌面层
+    // Create JsBridge and mount the WebView launcher layer
+    private fun setupWebView() {
+        val dm = resources.displayMetrics
+        val darkMode =
+            (resources.configuration.uiMode and Configuration.UI_MODE_NIGHT_MASK) ==
+                Configuration.UI_MODE_NIGHT_YES
+        val bridge = JsBridge(
+            deviceWidthPx = dm.widthPixels,
+            deviceHeightPx = dm.heightPixels,
+            density = dm.density,
+            darkMode = darkMode,
+        )
+        WebViewManager(this).attach(bridge)
+        Log.d(
+            TAG,
+            "setupWebView: attached WebView ${dm.widthPixels}x${dm.heightPixels}" +
+                " density=${dm.density} darkMode=$darkMode"
+        )
     }
 
     // 进入沉浸式全屏：隐藏状态栏与导航栏，滑动可临时唤出