feat(物品系统): 新增沙滩球物品及相关功能

refactor(武器卡片): 调整武器类型和颜色映射
style(UI): 更新武器名称标签样式
fix(实体基础): 修正物品掉落逻辑
perf(音频): 优化音频处理模式
docs(物品存储): 更新物品枚举和映射
build(资源): 添加沙滩球SVG资源文件
chore(资源): 更新篮球和棒球SVG资源

scripts/Statemachine/EntityBase.gd

@@ -50,11 +50,13 @@ var inventory = {
 	ItemStore.ItemType.BASEBALL: 500,
 	ItemStore.ItemType.BASKETBALL: 500,
 	ItemStore.ItemType.APPLE: 5,
+	ItemStore.ItemType.BEACHBALL: 0,
 }
 var inventoryMax = {
 	ItemStore.ItemType.BASEBALL: INF, # 无限
 	ItemStore.ItemType.BASKETBALL: INF,
 	ItemStore.ItemType.APPLE: 5,
+	ItemStore.ItemType.BEACHBALL: INF,
 }
 
 @export var defaultCooldownUnit: float = 100
@@ -237,6 +239,7 @@ func tryDie(by: BulletBase):
 	) or isBoss:
 		for i in randi_range(appleCount.x, appleCount.y):
 			ItemDropped.generate(ItemStore.ItemType.APPLE, 1, position + MathTool.randv2_range(GameRule.itemDroppedSpawnOffset))
+	ItemDropped.generate(ItemStore.ItemType.BEACHBALL, fields[FieldStore.Entity.MAX_HEALTH], position + MathTool.randv2_range(GameRule.itemDroppedSpawnOffset))
 	EffectController.create(preload("res://components/Effects/DeadBlood.tscn"), texture.global_position).shot()
 	await die()
 	if isPlayer() and UIState.player == self: