Refactor food items to use shared inherited scene.

Prefabs/combinable_item.gd

@@ -1,6 +1,8 @@
 class_name CombinableItem
 extends Node
 
+@export var enabled: bool = true
+
 @onready var combine_area_3d: Area3D = $Area3d
 @onready var _pickable: XRToolsPickable = get_parent() as XRToolsPickable
 
@@ -21,6 +23,8 @@ func _ready() -> void:
 	if not _food_item:
 		SweetLogger.warning("{0} requires a FoodItem sibling", [_pickable.name])
 		return
+	if not enabled:
+		return
 
 	# Detect items whether held (layer 17 "Held Objects") or loose
 	# (layer 3 "Pickable Objects"). Don't advertise a layer of our own.