Add the Metin2 app icon for Android, macOS and iOS

branding/icon/icon.svg (a cracked Metin stone with glowing runes, inside a studded gold ring, in front of
a blood moon over ink mountains) is the single source; build_icons.sh renders it with headless Chrome and
writes the committed outputs: Android legacy + adaptive mipmaps (wired into the manifest), the macOS
AppIcon.icns and the iOS AppIcon.appiconset. scripts/package_mac_app.sh wraps mt_native_render into a
local Metin2.app using that icon.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

android/app/src/main/AndroidManifest.xml

@@ -6,6 +6,8 @@
     <uses-permission android:name="android.permission.VIBRATE" />
 
     <application android:label="@string/app_name"
+        android:icon="@mipmap/ic_launcher"
+        android:roundIcon="@mipmap/ic_launcher_round"
         android:allowBackup="false"
         android:appCategory="game"
         android:isGame="true"