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/res/mipmap-anydpi-v26/ic_launcher.xml

@@ -0,0 +1,6 @@
+<?xml version="1.0" encoding="utf-8"?>
+<!-- Generated by branding/icon/build_icons.sh. -->
+<adaptive-icon xmlns:android="http://schemas.android.com/apk/res/android">
+    <background android:drawable="@mipmap/ic_launcher_background" />
+    <foreground android:drawable="@mipmap/ic_launcher_foreground" />
+</adaptive-icon>

android/app/src/main/res/mipmap-anydpi-v26/ic_launcher_round.xml

@@ -0,0 +1,6 @@
+<?xml version="1.0" encoding="utf-8"?>
+<!-- Generated by branding/icon/build_icons.sh. -->
+<adaptive-icon xmlns:android="http://schemas.android.com/apk/res/android">
+    <background android:drawable="@mipmap/ic_launcher_background" />
+    <foreground android:drawable="@mipmap/ic_launcher_foreground" />
+</adaptive-icon>