Add EventBus, SpeedRunManager, and GhostManager; implement ghost recording and playback features

scripts/GhostPlayer.cs

@@ -0,0 +1,48 @@
+using System.Collections.Generic;
+using Godot;
+
+namespace Mr.BrickAdventures.scripts;
+
+[GlobalClass]
+public partial class GhostPlayer : Node2D
+{
+    private List<GhostFrame> _playbackData = [];
+    private double _startTime = 0;
+    private int _currentFrameIndex = 0;
+    private bool _isPlaying = false;
+    
+    public void StartPlayback(List<GhostFrame> playbackData)
+    {
+        _playbackData = playbackData;
+        _startTime = Time.GetTicksMsec() / 1000.0;
+        _currentFrameIndex = 0;
+        _isPlaying = true;
+        SetProcess(true);
+    }
+
+    public override void _PhysicsProcess(double delta)
+    {
+        if (!_isPlaying || _playbackData.Count == 0) return;
+
+        var currentTime = (Time.GetTicksMsec() / 1000.0) - _startTime;
+
+        while (_currentFrameIndex + 1 < _playbackData.Count && _playbackData[_currentFrameIndex + 1].Timestamp <= currentTime)
+        {
+            _currentFrameIndex++;
+        }
+
+        if (_currentFrameIndex + 1 >= _playbackData.Count)
+        {
+            GlobalPosition = _playbackData[_currentFrameIndex].Position;
+            _isPlaying = false;
+            QueueFree();
+            return;
+        }
+        
+        var frameA = _playbackData[_currentFrameIndex];
+        var frameB = _playbackData[_currentFrameIndex + 1];
+        var t = (currentTime - frameA.Timestamp) / (frameB.Timestamp - frameA.Timestamp);
+
+        GlobalPosition = frameA.Position.Lerp(frameB.Position, (float)t);
+    }
+}