Add Android 16 API 36 compatibility with WindowInsetsController

- Create CustomQtActivity extending QtActivity for Android 16 support
- Replace deprecated setSystemUiVisibility with WindowInsetsController
- Maintain backward compatibility with older Android versions
- Fix header toolbar visibility issues on Android 16

🤖 Generated with [Claude Code](https://claude.ai/code)

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

src/android/AndroidManifest.xml

@@ -10,7 +10,7 @@
 
     <supports-screens android:largeScreens="true" android:normalScreens="true" android:anyDensity="true" android:smallScreens="true"/>
 	 <application android:hardwareAccelerated="true" android:debuggable="false" android:name="org.qtproject.qt5.android.bindings.QtApplication" android:label="qdomyos-zwift" android:extractNativeLibs="true" android:icon="@drawable/icon" android:usesCleartextTraffic="true">
-             <activity android:theme="@style/Theme.AppCompat" android:exported="true" android:configChanges="orientation|uiMode|screenLayout|screenSize|smallestScreenSize|layoutDirection|locale|fontScale|keyboard|keyboardHidden|navigation|mcc|mnc|density" android:name="org.qtproject.qt5.android.bindings.QtActivity" android:label="QZ" android:launchMode="singleTop">
+             <activity android:theme="@style/Theme.AppCompat" android:exported="true" android:configChanges="orientation|uiMode|screenLayout|screenSize|smallestScreenSize|layoutDirection|locale|fontScale|keyboard|keyboardHidden|navigation|mcc|mnc|density" android:name="org.cagnulen.qdomyoszwift.CustomQtActivity" android:label="QZ" android:launchMode="singleTop">
 		      <intent-filter>
 				    <action android:name="android.intent.action.MAIN"/>
 					 <category android:name="android.intent.category.LAUNCHER"/>

src/android/src/CustomQtActivity.java

@@ -0,0 +1,34 @@
+package org.cagnulen.qdomyoszwift;
+
+import android.os.Build;
+import android.os.Bundle;
+import android.view.View;
+import android.view.WindowInsets;
+import android.view.WindowInsetsController;
+import org.qtproject.qt5.android.bindings.QtActivity;
+
+public class CustomQtActivity extends QtActivity {
+
+    @Override
+    public void onCreate(Bundle savedInstanceState) {
+        super.onCreate(savedInstanceState);
+        
+        // Handle Android 16 API 36 WindowInsetsController for fullscreen support
+        if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.R) {
+            // Android 11 (API 30) and above - use WindowInsetsController
+            getWindow().setDecorFitsSystemWindows(false);
+            WindowInsetsController controller = getWindow().getDecorView().getWindowInsetsController();
+            if (controller != null) {
+                controller.hide(WindowInsets.Type.statusBars() | WindowInsets.Type.navigationBars());
+                controller.setSystemBarsBehavior(WindowInsetsController.BEHAVIOR_SHOW_TRANSIENT_BARS_BY_SWIPE);
+            }
+        } else {
+            // Fallback for older Android versions (API < 30)
+            getWindow().getDecorView().setSystemUiVisibility(
+                View.SYSTEM_UI_FLAG_HIDE_NAVIGATION |
+                View.SYSTEM_UI_FLAG_FULLSCREEN |
+                View.SYSTEM_UI_FLAG_IMMERSIVE_STICKY
+            );
+        }
+    }
+}