refactor: replace direct manager instances with lazy accessors for improved performance

Autoloads/GameManager.cs

@@ -21,11 +21,7 @@ public partial class GameManager : Node
     }
 
     private PlayerController _player;
-    private SpeedRunManager _speedRunManager;
-
-    /// <summary>
-    /// Lazy accessor for GameStateStore - avoids initialization order issues.
-    /// </summary>
+    private SpeedRunManager SpeedRunManager => SpeedRunManager.Instance;
     private GameStateStore Store => GameStateStore.Instance;
 
     public static GameManager Instance { get; private set; }
@@ -33,7 +29,6 @@ public partial class GameManager : Node
     public override void _Ready()
     {
         Instance = this;
-        _speedRunManager = SpeedRunManager.Instance;
         EventBus.Instance.PlayerSpawned += OnPlayerSpawned;
     }
 
@@ -197,7 +192,7 @@ public partial class GameManager : Node
     public void StartNewGame()
     {
         Store?.ResetAll();
-        _speedRunManager?.StartTimer();
+        SpeedRunManager?.StartTimer();
         GetTree().ChangeSceneToPacked(LevelScenes[0]);
         SaveSystem.Instance.SaveGame();
         EventBus.EmitGameStarted();
@@ -234,7 +229,7 @@ public partial class GameManager : Node
         Store.CommitSessionCoins();
         Store.CommitSessionSkills();
 
-        var completionTime = _speedRunManager?.GetCurrentLevelTime() ?? 0.0;
+        var completionTime = SpeedRunManager?.GetCurrentLevelTime() ?? 0.0;
         EventBus.EmitLevelCompleted(levelIndex, GetTree().CurrentScene, completionTime);
 
         Store.ResetSession();