fix(ios): add @objc annotation to SceneDelegate for runtime visibility

Added @objc annotation to SceneDelegate:

Objective-C Runtime:
- Added @objc(SceneDelegate) annotation
- Makes class visible to Objective-C runtime
- Required for Info.plist class name resolution

Fixes:
- SceneDelegate loading: class can now be found by iOS runtime
- Info.plist resolution: UISceneDelegateClassName can now resolve
- ViewController creation: SceneDelegate can now instantiate ViewController

Result: SceneDelegate should now be loadable by iOS runtime

test-apps/ios-test-app/App/App/SceneDelegate.swift

@@ -18,6 +18,7 @@ import os.log
  * Required for modern iOS apps using scene-based architecture
  */
 @available(iOS 13.0, *)
+@objc(SceneDelegate)
 class SceneDelegate: UIResponder, UIWindowSceneDelegate {
 
     var window: UIWindow?