feat: 添加新武器彩虹旗和紫水晶簇，调整饲料属性和数值

refactor: 重构子弹生成逻辑，支持分裂和折射效果

fix: 修复掉落物拾取范围和碰撞检测问题

style: 优化UI显示，添加武器品质和类型标签

docs: 更新字段描述，调整部分饲料名称和分类

perf: 优化数学工具函数，添加随机数处理工具

test: 调整波次生成逻辑，添加新敌人类型

build: 添加新资源文件和相关导入配置

components/UI/ItemDropped.tscn

@@ -1,8 +1,11 @@
-[gd_scene load_steps=16 format=3 uid="uid://cxcvc1rjvm8i2"]
+[gd_scene load_steps=17 format=3 uid="uid://cxcvc1rjvm8i2"]
 
 [ext_resource type="Script" path="res://scripts/Statemachine/ItemDropped.gd" id="1_v2djl"]
 [ext_resource type="Texture2D" uid="uid://bks8jmctleina" path="res://resources/items/baseball.svg" id="2_4hl42"]
 
+[sub_resource type="PhysicsMaterial" id="PhysicsMaterial_1ishj"]
+bounce = 0.5
+
 [sub_resource type="Animation" id="Animation_5i70v"]
 length = 0.001
 tracks/0/type = "bezier"
@@ -83,7 +86,7 @@ _data = {
 }
 
 [sub_resource type="CircleShape2D" id="CircleShape2D_7lt1c"]
-radius = 2.0
+radius = 14.0357
 
 [sub_resource type="Curve" id="Curve_11h7l"]
 _data = [Vector2(0, 0.5), 0.0, 0.0, 0, 0, Vector2(1, 0), 0.0, 0.0, 0, 0]
@@ -130,6 +133,9 @@ alpha_curve = SubResource("CurveTexture_u4ger")
 [node name="ItemDropped" type="RigidBody2D"]
 collision_layer = 2
 collision_mask = 2
+physics_material_override = SubResource("PhysicsMaterial_1ishj")
+contact_monitor = true
+max_contacts_reported = 1
 script = ExtResource("1_v2djl")
 metadata/_edit_vertical_guides_ = [15.0, -15.0]