New boxes (#21439)

* Thoroughly resprites boxes. They're now more modular and, importantly,
colorable.
* Resprites cardboard, as a material.
* Repaths boxes behind the scenes to be more object-oriented, with boxes
being resorted into their own subtypes. You might notice this in the
gargantuan amount of files this PR changes.

Part of a bigger (yet modestly-sized still) resprites project. Atomized
the boxes bit into this PR specifically so that any conflicts don't
destroy any other spriting PRs.

<img width="652" height="273" alt="image"
src="https://github.com/user-attachments/assets/5590b22d-c9d7-49b5-9adf-0b6e01a6962b"
/>

<img width="383" height="345" alt="image"
src="https://github.com/user-attachments/assets/aab83040-2d5d-4283-b019-3d6bed2e3e47"
/>

<img width="142" height="343" alt="image"
src="https://github.com/user-attachments/assets/75a98d36-0171-4e48-9dec-de5511f35d39"
/>

<img width="127" height="225" alt="image"
src="https://github.com/user-attachments/assets/a1ff8b1b-bd2a-4c0d-b538-32fe401724c3"
/>

<img width="334" height="399" alt="image"
src="https://github.com/user-attachments/assets/e41330ac-ed4a-4e81-a87a-5ba901b47b5c"
/>

code/modules/holidays/christmas/props.dm

@@ -104,7 +104,7 @@
 	var/gift_type = pick(
 		/obj/item/storage/wallet,
 		/obj/item/storage/photo_album,
-		/obj/item/storage/box/snappops,
+		/obj/item/storage/box/unique/snappops,
 		/obj/item/storage/box/fancy/crayons,
 		/obj/item/storage/belt/champion,
 		/obj/item/soap/deluxe,
@@ -202,7 +202,7 @@
 		/obj/random/wizard_dressup,
 		/obj/item/storage/wallet,
 		/obj/item/storage/photo_album,
-		/obj/item/storage/box/snappops,
+		/obj/item/storage/box/unique/snappops,
 		/obj/item/storage/box/fancy/crayons,
 		/obj/item/soap/deluxe,
 		/obj/item/pen/invisible,
@@ -294,7 +294,7 @@
 		/obj/item/device/paicard,
 		/obj/item/clothing/accessory/horrible,
 		/obj/item/clothing/shoes/heels,
-		/obj/item/storage/box/donkpockets,
+		/obj/item/storage/box/unique/donkpockets,
 		/obj/item/reagent_containers/glass/beaker/teapot,
 		/obj/item/device/flashlight/lantern,
 		/obj/item/clothing/mask/balaclava,
@@ -366,7 +366,7 @@
 		/mob/living/simple_animal/parrot,
 		/mob/living/simple_animal/hostile/commanded/dog/pug,
 		/obj/item/target/alien,
-		/obj/item/storage/box/candy)
+		/obj/item/storage/box/large/candy)
 
 	return picked_gift_type