FlutterSExtensions class

Manages shared Flutter context and view dependencies for extension getters.

This singleton-style utility stores a FlutterView and derived MediaQueryData so extension properties like 0.2.screenWidth can be accessed without passing a BuildContext explicitly.

Initialization patterns:

• Lazy: If you don't call init, the first access attempts a lazy initialization using WidgetsBinding.instance.platformDispatcher.views.first. This generally works after runApp, but will throw if no view is available (e.g., early in tests).
• Explicit: Call init with a BuildContext as early as possible. A convenient place is MaterialApp.builder or WidgetsApp.builder:

MaterialApp(
  builder: (context, child) {
    FlutterSExtensions.update(context); // keeps data fresh on hot reload
    return child!;
  },
  home: const MyHomePage(),
)

Hot reload: Use update inside a widget builder to refresh the stored FlutterView and MediaQueryData whenever the tree rebuilds, including hot reloads and route changes.