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

scripts/UI/DeathScreen.cs

@@ -1,5 +1,4 @@
 using Godot;
-using Mr.BrickAdventures;
 using Mr.BrickAdventures.Autoloads;
 using Mr.BrickAdventures.scripts.Resources;
 using Mr.BrickAdventures.scripts.State;
@@ -15,13 +14,11 @@ public partial class DeathScreen : Control
     [Export] public float TimeoutTime { get; set; } = 2.0f;
     [Export] public Godot.Collections.Array<Node> NodesToDisable { get; set; } = new();
 
-    private GameManager _gameManager;
+    private GameManager GameManager => GameManager.Instance;
     private Timer _timer;
 
     public override void _Ready()
     {
-        _gameManager = GameManager.Instance;
-
         // Subscribe to lives changed event for reactive updates
         EventBus.Instance.LivesChanged += OnLivesChanged;
     }
@@ -74,7 +71,7 @@ public partial class DeathScreen : Control
 
     public void OnPlayerDeath()
     {
-        if (_gameManager == null) return;
+        if (GameManager == null) return;
 
         ToggleNodes();
         SetLabels();