Refactor food items to use shared inherited scene.

Prefabs/build_mode_controller.gd

@@ -25,13 +25,16 @@ func _set_stations_enabled(value: bool) -> void:
 			station.enabled = value
 
 
-# Despawn all food_items unless it's in a "persistent_inventory" snap_zone
+# Despawn all despawnable pickables unless it's in a "persistent_inventory"
+# snap_zone. Permanent fixtures (e.g. a station's knife) opt out entirely by
+# having no DespawningItem child, or a disabled one.
 func despawn_unheld_pickables():
 	var root = get_tree().get_root()
 	var pickables: Array[Node] = []
 	_collect_pickables(root, pickables)
 	for pickable in pickables:
-		if not Helper.find_food_item(pickable):
+		var despawning_item := pickable.get_node_or_null("DespawningItem") as DespawningItem
+		if not despawning_item or not despawning_item.enabled:
 			continue
 		var held_by: Node = pickable.get_picked_up_by()
 		if not held_by:

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.

Prefabs/despawning_item.gd

@@ -1,6 +1,8 @@
 extends Node
 class_name DespawningItem
 
+@export var enabled: bool = true
+
 @export var time_to_despawn: float = 8
 
 # The minimum speed required to reset despawn timer.
@@ -20,9 +22,12 @@ func _ready() -> void:
 	if not _rigid:
 			SweetLogger.error("{0} must be a grandchild of a RigidBody3D", [name])
 			return
-		
+
 
 func _process(delta: float) -> void:
+	if not enabled:
+		return
+
 	# Despawning is a world decision, so only the owner of world logic runs the
 	# clock. Every peer used to run its own copy: the countdown drifted between
 	# them and the blink below toggled `visible` locally, so the same item was