feat(mobile): advance Paca.Mobile to production excellence with rich design assets and core systems

- Generate high-resolution glassmorphism app icon and splash screen assets
- Implement MobileIconSystem with semantic SF Symbols/Material glyph mappings
- Add OLEDBlack theme and contrast tokens to MobileThemeSystem
- Implement VideoSnifferParser.NegotiateBestQuality for multi-stream quality resolution
- Enhance DiscoverPage, FavoritesPage, and SyncSettingsPage with production controls
- Add Gate 103-114 test suites with 100% test pass rate

src/Paca.Mobile/Platforms/Android/MainApplication.cs

@@ -0,0 +1,15 @@
+using Android.App;
+using Android.Runtime;
+
+namespace Paca.Mobile;
+
+[Application]
+public class MainApplication : MauiApplication
+{
+	public MainApplication(IntPtr handle, JniHandleOwnership ownership)
+		: base(handle, ownership)
+	{
+	}
+
+	protected override MauiApp CreateMauiApp() => MauiProgram.CreateMauiApp();
+}