Add new skills: Double Jump, Ground Pound, Brick Armor, and Brick Shield; implement skill removal signal in SkillManager (#11)

scripts/components/XRayVisionSkillComponent.cs

@@ -0,0 +1,51 @@
+using Godot;
+using Mr.BrickAdventures.scripts.interfaces;
+using Mr.BrickAdventures.scripts.Resources;
+
+namespace Mr.BrickAdventures.scripts.components;
+
+[GlobalClass]
+public partial class XRayVisionSkillComponent : Node, ISkill
+{
+    [Export(PropertyHint.Layers2DRender)] public uint SecretLayer { get; set; }
+    [Export] public float Duration { get; set; } = 5.0f;
+    
+    private Camera2D _camera;
+    private Viewport _viewport;
+    private uint _originalVisibilityLayer;
+    private Timer _timer;
+    
+    public void Initialize(Node owner, SkillData data)
+    {
+        _viewport = GetViewport();
+        _camera = GetViewport().GetCamera2D();
+        _timer = new Timer { OneShot = true };
+        AddChild(_timer);
+        _timer.Timeout += Deactivate;
+    }
+
+    public void Activate()
+    {
+        if (_camera == null) return;
+        
+        _originalVisibilityLayer = _camera.VisibilityLayer;
+        _camera.VisibilityLayer |= SecretLayer;
+        _timer.Start(Duration);
+    }
+
+    public void Deactivate()
+    {
+        if (_camera != null)
+        {
+            _camera.VisibilityLayer = _originalVisibilityLayer;
+        }
+    }
+
+    public void ApplyUpgrade(SkillUpgrade upgrade)
+    {
+        if (upgrade.Properties.TryGetValue("duration", out var newDuration))
+        {
+            Duration = (float)newDuration;
+        }
+    }
+}