feat: native Android audio via Media3 ExoPlayer + full NSBridge JS adapter

- Replace legacy MediaBrowserServiceCompat/MediaSessionCompat with
  Media3 MediaSessionService (MusicService.kt) + ExoPlayer set to
  WAKE_MODE_NETWORK — holds WakeLock + WifiLock through Doze so audio
  plays uninterrupted on locked screen
- Media3 manages the notification; no manual NotificationCompat.Builder
  → no disappear/reappear flicker when skipping tracks
- Full bidirectional bridge:
    JS → native: window.NSBridge.* (WebBridge.kt, 13 methods)
    Native → JS: window.NSPlayer.* callbacks (onReady, onTrackChanged,
      onPositionUpdate, onPlaybackStateChanged, onQueueEnded, onError)
- player.js: progressive enhancement — all playback routes through
  NSBridge when running inside the wrapper, falls back to S.audio on
  plain PWA/browser; removes all window.Android.* calls
- main.js: guard _onForeground mediaSession playbackState setter behind
  !window.NSBridge so native Media3 session is never stomped
- ProGuard rules updated to keep WebBridge @JavascriptInterface methods
  and Media3 classes
- bridge-test.html: manual integration test page for every bridge method

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

android/app/src/main/AndroidManifest.xml

@@ -0,0 +1,51 @@
+<?xml version="1.0" encoding="utf-8"?>
+<manifest xmlns:android="http://schemas.android.com/apk/res/android">
+
+    <uses-permission android:name="android.permission.INTERNET"/>
+    <uses-permission android:name="android.permission.ACCESS_NETWORK_STATE"/>
+    <uses-permission android:name="android.permission.FOREGROUND_SERVICE"/>
+    <uses-permission android:name="android.permission.FOREGROUND_SERVICE_MEDIA_PLAYBACK"/>
+    <uses-permission android:name="android.permission.POST_NOTIFICATIONS"/>
+    <uses-permission android:name="android.permission.WAKE_LOCK"/>
+
+    <application
+        android:allowBackup="true"
+        android:icon="@drawable/ic_launcher"
+        android:label="@string/app_name"
+        android:roundIcon="@drawable/ic_launcher"
+        android:supportsRtl="true"
+        android:theme="@style/Theme.NovaSonic"
+        android:networkSecurityConfig="@xml/network_security_config"
+        android:usesCleartextTraffic="true"
+        android:largeHeap="true">
+
+        <activity
+            android:name=".MainActivity"
+            android:exported="true"
+            android:configChanges="orientation|screenSize|keyboardHidden|smallestScreenSize|screenLayout"
+            android:windowSoftInputMode="adjustResize"
+            android:launchMode="singleTask">
+            <intent-filter>
+                <action android:name="android.intent.action.MAIN"/>
+                <category android:name="android.intent.category.LAUNCHER"/>
+            </intent-filter>
+        </activity>
+
+        <service
+            android:name=".MusicService"
+            android:foregroundServiceType="mediaPlayback"
+            android:exported="true">
+            <intent-filter>
+                <action android:name="androidx.media3.session.MediaLibraryService"/>
+                <action android:name="android.media.browse.MediaBrowserService"/>
+            </intent-filter>
+        </service>
+
+        <!-- Android Auto support -->
+        <meta-data
+            android:name="com.google.android.gms.car.application"
+            android:resource="@xml/automotive_app_desc"/>
+
+    </application>
+
+</manifest>