feat: pr suggestion

lib/game/bloc/game_bloc.dart

@@ -30,7 +30,10 @@ class GameBloc extends Bloc<GameEvent, GameState> {
   }
 
   void _onBonusLetterActivated(BonusLetterActivated event, Emitter emit) {
-    final newBonusLetters = [...state.activatedBonusLetters, event.letter];
+    final newBonusLetters = [
+      ...state.activatedBonusLetters,
+      event.letterIndex,
+    ];
 
     if (newBonusLetters.length == _bonusLettersCount) {
       emit(

lib/game/bloc/game_event.dart

@@ -26,10 +26,10 @@ class Scored extends GameEvent {
 }
 
 class BonusLetterActivated extends GameEvent {
-  const BonusLetterActivated(this.letter);
+  const BonusLetterActivated(this.letterIndex);
 
-  final int letter;
+  final int letterIndex;
 
   @override
-  List<Object?> get props => [letter];
+  List<Object?> get props => [letterIndex];
 }