fix(android): move MainActivity to the package the manifest looks for

The app crashed on launch with ClassNotFoundException for
es.freetimelab.farolero.game.MainActivity: 374c6ae added the .game suffix to
namespace and applicationId but left the Kotlin source in
es.freetimelab.farolero, so the manifest asked for a class that was never
compiled under that name. Every release built since then died on startup,
including the one already published to internal testing.

Also requests edge-to-edge explicitly now that the app targets 35, rather
than relying on the Flutter default.

Verified on a physical device running Android 16: installs, launches and
stays alive with no crash, and the bottom action buttons sit clear of the
navigation bar.

android/app/src/main/kotlin/es/freetimelab/farolero/game/MainActivity.kt

@@ -1,4 +1,4 @@
-package es.freetimelab.farolero
+package es.freetimelab.farolero.game
 
 import io.flutter.embedding.android.FlutterActivity
 

lib/main.dart

@@ -15,6 +15,12 @@ import 'pantallas/pantalla_principal.dart';
 void main() {
   WidgetsFlutterBinding.ensureInitialized();
   SystemChrome.setPreferredOrientations([DeviceOrientation.portraitUp]);
+  // Desde targetSdk 35 el dibujado de borde a borde es obligatorio. Se pide
+  // explícitamente en vez de confiar en el valor por defecto de Flutter; son
+  // las pantallas, vía SafeArea, las que apartan su contenido de las barras.
+  // Con navegación de 3 botones el sistema pinta igualmente un velo tras ellos
+  // y eso no lo controla la app.
+  SystemChrome.setEnabledSystemUIMode(SystemUiMode.edgeToEdge);
   SystemChrome.setSystemUIOverlayStyle(
     const SystemUiOverlayStyle(
       statusBarColor: Colors.transparent,