feat(相机管理): 添加CameraManager类并实现玩家跟随

refactor(物品展示): 修改ItemShow状态机自动隐藏逻辑

feat(游戏逻辑): 添加玩家死亡时的游戏结束界面

style(场景配置): 调整World场景中相机节点位置和偏移

feat(UI): 为ItemShow添加显示动画并更新动画库

scripts/Tools/CameraManager.gd

@@ -1 +1,11 @@
+@tool
 extends Camera2D
+class_name CameraManager
+
+static var camera: Camera2D = null
+
+func _ready():
+	camera = self
+func _physics_process(_delta):
+	if is_instance_valid(UIState.player):
+		position = UIState.player.position