feat(障碍物系统): 添加草墙障碍物及相关功能

实现草墙障碍物系统，包括以下主要变更：
- 新增草墙障碍物资源、脚本和场景
- 添加障碍物状态显示UI
- 扩展组件管理器支持障碍物类型
- 修改子弹系统以支持对障碍物的碰撞检测
- 调整实体碰撞层设置
- 为公鸡角色添加草墙武器

新增功能允许玩家放置可阻挡敌人的草墙障碍物，并显示其生命值状态

components/UI/ItemDropped.tscn

@@ -1,6 +1,6 @@
 [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="Script" uid="uid://cfxrtel5gjia0" 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"]
@@ -81,8 +81,8 @@ tracks/2/keys = {
 
 [sub_resource type="AnimationLibrary" id="AnimationLibrary_2q7p1"]
 _data = {
-"RESET": SubResource("Animation_5i70v"),
-"collect": SubResource("Animation_l0b83")
+&"RESET": SubResource("Animation_5i70v"),
+&"collect": SubResource("Animation_l0b83")
 }
 
 [sub_resource type="CircleShape2D" id="CircleShape2D_7lt1c"]
@@ -96,7 +96,7 @@ point_count = 2
 curve = SubResource("Curve_11h7l")
 
 [sub_resource type="Curve" id="Curve_h22hm"]
-min_value = -1.0
+_limits = [-1.0, 1.0, 0.0, 1.0]
 _data = [Vector2(0, 1), 0.0, 0.0, 0, 0, Vector2(1, -1), 0.0, 0.0, 0, 0]
 point_count = 2
 
@@ -131,8 +131,8 @@ color_initial_ramp = SubResource("GradientTexture1D_5p7rs")
 alpha_curve = SubResource("CurveTexture_u4ger")
 
 [node name="ItemDropped" type="RigidBody2D"]
-collision_layer = 2
-collision_mask = 2
+collision_layer = 512
+collision_mask = 512
 physics_material_override = SubResource("PhysicsMaterial_1ishj")
 contact_monitor = true
 max_contacts_reported = 1
@@ -147,7 +147,7 @@ texture = ExtResource("2_4hl42")
 [node name="animator" type="AnimationPlayer" parent="texture"]
 unique_name_in_owner = true
 libraries = {
-"": SubResource("AnimationLibrary_2q7p1")
+&"": SubResource("AnimationLibrary_2q7p1")
 }
 
 [node name="hitbox" type="CollisionShape2D" parent="."]