refactor: renamed ballsLeft to balls

lib/game/bloc/game_bloc.dart

@@ -6,14 +6,14 @@ part 'game_event.dart';
 part 'game_state.dart';
 
 class GameBloc extends Bloc<GameEvent, GameState> {
-  GameBloc() : super(const GameState(score: 0, ballsLeft: 3)) {
+  GameBloc() : super(const GameState(score: 0, balls: 3)) {
     on<BallLost>(_onBallLost);
     on<Scored>(_onScored);
   }
 
   void _onBallLost(BallLost event, Emitter emit) {
-    if (state.ballsLeft > 0) {
+    if (state.balls > 0) {
-      emit(state.copyWith(ballsLeft: state.ballsLeft - 1));
+      emit(state.copyWith(balls: state.balls - 1));
     }
   }
 

lib/game/bloc/game_state.dart

@@ -3,27 +3,27 @@ part of 'game_bloc.dart';
 class GameState extends Equatable {
   const GameState({
     required this.score,
-    required this.ballsLeft,
+    required this.balls,
   });
 
   final int score;
-  final int ballsLeft;
+  final int balls;
 
-  bool get isGameOver => ballsLeft == 0;
+  bool get isGameOver => balls == 0;
 
   GameState copyWith({
     int? score,
-    int? ballsLeft,
+    int? balls,
   }) {
     return GameState(
       score: score ?? this.score,
-      ballsLeft: ballsLeft ?? this.ballsLeft,
+      balls: balls ?? this.balls,
     );
   }
 
   @override
   List<Object?> get props => [
         score,
-        ballsLeft,
+        balls,
       ];
 }