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

scripts/Statemachine/ObstacleBase.gd

@@ -0,0 +1,64 @@
+extends StaticBody2D
+class_name ObstacleBase
+
+signal healthChanged(newHealth: float)
+
+@export var healthMax: float = 100
+@export var penerateResistance: float = 0
+@export var blockPlayer: bool = false
+@export var blockEnemy: bool = false
+
+@onready var statebar: ObstacleStateBar = $%statebar
+@onready var texture: AnimatedSprite2D = $%texture
+@onready var hitbox: CollisionShape2D = $%hitbox
+var health: float = 0
+var launcher: EntityBase = null
+
+func _ready():
+	health = healthMax
+	if blockPlayer:
+		collision_layer |= EntityBase.Layers.PLAYER
+		collision_mask |= EntityBase.Layers.PLAYER
+	if blockEnemy:
+		collision_layer |= EntityBase.Layers.ENEMY
+		collision_mask |= EntityBase.Layers.ENEMY
+	healthChanged.connect(
+		func(newHealth):
+			statebar.healthBar.maxValue = healthMax
+			statebar.healthBar.setCurrent(newHealth)
+	)
+func _process(_delta):
+	statebar.global_rotation = 0
+	statebar.applyText()
+
+func initHealth(maxHealth: float):
+	healthMax = maxHealth
+	health = healthMax
+	statebar.forceSync()
+	statebar.applyText()
+func takeDamage(damage: float):
+	health -= damage
+	healthChanged.emit(health)
+	if health <= 0:
+		tryDie()
+func tryDie():
+	die()
+	queue_free()
+
+func die():
+	pass
+
+static func generate(
+	obstacle: PackedScene,
+	spawnPosition: Vector2,
+	spawnRotation: float = 0,
+	itsLauncher: EntityBase = null,
+	addToWorld: bool = true
+) -> ObstacleBase:
+	var instance: ObstacleBase = obstacle.instantiate()
+	instance.position = spawnPosition
+	instance.rotation = spawnRotation
+	instance.launcher = itsLauncher
+	if addToWorld:
+		WorldManager.rootNode.spawn(instance)
+	return instance