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

objects/ui/speed_run_hud.tscn

@@ -0,0 +1,26 @@
+[gd_scene load_steps=2 format=3 uid="uid://kh85xqo6j848"]
+
+[ext_resource type="Script" uid="uid://0jfdx0hufs55" path="res://scripts/UI/SpeedRunHud.cs" id="1_uwqm0"]
+
+[node name="SpeedRunHud" type="Control" node_paths=PackedStringArray("_timerLabel")]
+layout_mode = 3
+anchors_preset = 15
+anchor_right = 1.0
+anchor_bottom = 1.0
+grow_horizontal = 2
+grow_vertical = 2
+script = ExtResource("1_uwqm0")
+_timerLabel = NodePath("Label")
+metadata/_custom_type_script = "uid://0jfdx0hufs55"
+
+[node name="Label" type="Label" parent="."]
+layout_mode = 1
+anchors_preset = 15
+anchor_right = 1.0
+anchor_bottom = 1.0
+grow_horizontal = 2
+grow_vertical = 2
+text = "00:00:00"
+horizontal_alignment = 1
+vertical_alignment = 1
+uppercase = true