feat(task-0002): implement state controller interface with cancellation support and update task status

- Refactor BootStatesController to implement IStatesController interface
- Move state dictionary creation into constructor, remove static helper method
- Add CancellationToken validation before state transitions in StatesController
- Track current state presence with _hasCurrentState flag for safety
- Update TASK-0002 with Ready status

Выполнена задача TASK-0002 и обновлён статус:
- Рефакторинг BootStatesController для реализации интерфейса IStatesController
- Перемещено создание словаря состояний в конструктор, удалён статический вспомогательный метод
- Добавлена валидация CancellationToken перед переходами между состояниями в StatesController
- Добавлен флаг _hasCurrentState для отслеживания текущего состояния
- Обновлён статус TASK-0002 до Ready

Agent/Task/TASK-0002.md

@@ -1,5 +1,9 @@
 # TASK-0002: Базовая архитектура Boot Flow
 
+## Статус
+
+Ready
+
 ## Цель
 
 Создать минимальную архитектурную основу для boot flow: сервисный lifecycle, state-контракты и generic state controller.

Assets/Scripts/Boot/States/BootStatesController.cs

@@ -1,29 +1,31 @@
 using System.Collections.Generic;
+using System.Threading;
+using Cysharp.Threading.Tasks;
 using QuizPleaseTest.Common.StateMachine;
 
 namespace QuizPleaseTest.Boot.States
 {
-    public class BootStatesController : StatesController<BootStateCode>
+    public class BootStatesController : IStatesController<BootStateCode>
     {
+        private readonly StatesController<BootStateCode> _statesController;
+
         public BootStatesController(
             SplashState splashState,
             LoadState loadState,
             MenuState menuState)
-            : base(CreateStates(splashState, loadState, menuState))
         {
-        }
-
-        private static IReadOnlyDictionary<BootStateCode, IState> CreateStates(
-            SplashState splashState,
-            LoadState loadState,
-            MenuState menuState)
-        {
-            return new Dictionary<BootStateCode, IState>
+            _statesController = new StatesController<BootStateCode>(
+                new Dictionary<BootStateCode, IState>
                 {
                     { BootStateCode.Splash, splashState },
                     { BootStateCode.Load, loadState },
                     { BootStateCode.Menu, menuState }
-            };
+                });
+        }
+
+        public UniTask EnterStateAsync(BootStateCode code, CancellationToken ct)
+        {
+            return _statesController.EnterStateAsync(code, ct);
         }
     }
 }

Assets/Scripts/Common/StateMachine/StatesController.cs

@@ -9,6 +9,7 @@ namespace QuizPleaseTest.Common.StateMachine
     {
         private readonly IReadOnlyDictionary<TEnum, IState> _states;
         private IState _currentState;
+        private bool _hasCurrentState;
 
         public StatesController(IReadOnlyDictionary<TEnum, IState> states)
         {
@@ -17,18 +18,25 @@ namespace QuizPleaseTest.Common.StateMachine
 
         public async UniTask EnterStateAsync(TEnum code, CancellationToken ct)
         {
+            ct.ThrowIfCancellationRequested();
+
             if (!_states.TryGetValue(code, out IState newState))
             {
                 throw new InvalidOperationException($"State is not registered: {code}");
             }
 
-            if (_currentState != null)
+            if (_hasCurrentState)
             {
                 await _currentState.ExitAsync(ct);
+                _currentState = null;
+                _hasCurrentState = false;
             }
 
+            ct.ThrowIfCancellationRequested();
+
+            await newState.EnterAsync(ct);
             _currentState = newState;
-            await _currentState.EnterAsync(ct);
+            _hasCurrentState = true;
         }
     }
 }