Pacxon (#12)

* Add GridMovementAbility and PacXonGridInteractor for grid-based movement; integrate with PlayerController and PacXonLevel

* Add GhostMovementComponent and PacXonTrailComponent; integrate ghost movement and trail features in PacXonLevel

* Update main menu button focus and add new movement abilities; adjust player and ghost initialization in PacXonLevel

scripts/components/PacXonTrailComponent.cs

@@ -0,0 +1,67 @@
+using System.Collections.Generic;
+using Godot;
+
+namespace Mr.BrickAdventures.scripts.components;
+
+[GlobalClass]
+public partial class PacXonTrailComponent : Line2D
+{
+    private PacXonGridInteractor _gridInteractor;
+    private readonly List<Vector2> _trailPoints = [];
+    
+    public void Initialize(PacXonGridInteractor interactor)
+    {
+        _gridInteractor = interactor;
+        _gridInteractor.TrailStarted += OnTrailStarted;
+        _gridInteractor.TrailExtended += OnTrailExtended;
+        _gridInteractor.TrailCleared += OnTrailCleared;
+
+        Width = 8;
+        DefaultColor = new Color("#a6f684");
+        JointMode = LineJointMode.Round;
+        BeginCapMode = LineCapMode.Round;
+        EndCapMode = LineCapMode.Round;
+    }
+    
+    public override void _ExitTree()
+    {
+        if (_gridInteractor != null)
+        {
+            _gridInteractor.TrailStarted -= OnTrailStarted;
+            _gridInteractor.TrailExtended -= OnTrailExtended;
+            _gridInteractor.TrailCleared -= OnTrailCleared;
+        }
+    }
+    
+    private void OnTrailStarted(Vector2 startPosition)
+    {
+        _trailPoints.Clear();
+        _trailPoints.Add(ToLocal(startPosition));
+        _trailPoints.Add(ToLocal(startPosition));
+        UpdateTrail();
+    }
+
+    private void OnTrailExtended(Vector2 newPosition)
+    {
+        if (_trailPoints.Count > 0)
+        {
+            _trailPoints[^1] = ToLocal(newPosition);
+        }
+        UpdateTrail();
+    }
+
+    private void OnTrailCleared()
+    {
+        _trailPoints.Clear();
+        UpdateTrail();
+    }
+
+    private void UpdateTrail()
+    {
+        ClearPoints();
+        foreach (var point in _trailPoints)
+        {
+            AddPoint(point);
+        }
+    }
+}