feat: 添加掉落物功能，更新饲料和物品显示，重构相关UI组件

scripts/Tools/GameRule.gd

@@ -3,4 +3,5 @@ class_name GameRule
 static var allowFriendlyFire: bool = false # 是否允许友军伤害
 static var bulletSpeedMultiplier: float = 1 # 子弹速度倍率
 static var damageOffset: float = 0.2 # 伤害随机浮动比例，默认20%，即10的基础伤害会应用为8~12
-static var damageLabelSpawnOffset: float = 10 # 伤害标签生成位置的随机偏移
+static var damageLabelSpawnOffset: float = 10 # 伤害标签生成位置的随机偏移
+static var itemDroppedSpawnOffset: float = 10 # 掉落物生成位置的随机偏移

scripts/Tools/ItemStore.gd

@@ -12,4 +12,6 @@ static var nameMap = {
 static var idMap = {
 	ItemType.BASEBALL: "baseball",
 	ItemType.BASKETBALL: "basketball"
-}
+}
+static func getTexture(type: ItemType) -> Texture2D:
+	return load("res://resources/items/%s.svg" % idMap[type])