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/Statemachine/ItemDropped.gd

@@ -0,0 +1,39 @@
+extends RigidBody2D
+class_name ItemDropped
+
+var item: ItemStore.ItemType = ItemStore.ItemType.BASEBALL
+var stackCount: int = 1
+var targetPlayer: EntityBase = null
+
+@onready var texture: Sprite2D = $"%texture"
+
+func _process(_delta):
+	texture.texture = ItemStore.getTexture(item)
+func _physics_process(_delta):
+	if !is_instance_valid(targetPlayer):
+		targetPlayer = findPlayer()
+	if is_instance_valid(targetPlayer):
+		apply_central_force((targetPlayer.position - position).normalized() * 1000)
+func findPlayer() -> EntityBase:
+	var result = null
+	var lastDistance = INF
+	for player in get_tree().get_nodes_in_group("players"):
+		if player is EntityBase:
+			if position.distance_to(player.position) < lastDistance:
+				lastDistance = position.distance_to(player.position)
+				result = player
+	return result
+
+static func generate(
+		itemType: ItemStore.ItemType,
+		count: int,
+		spawnPosition: Vector2,
+		addToWorld: bool = true
+	):
+	var instance: ItemDropped = preload("res://components/UI/ItemDropped.tscn").instantiate()
+	instance.item = itemType
+	instance.stackCount = count
+	instance.position = spawnPosition
+	if addToWorld:
+		WorldManager.rootNode.call_deferred("add_child", instance)
+	return instance