Adds purity seals (#93496)

## About The Pull Request

Adds purity seals for the chaplain's use. Calling them cheap stickers
may get you branded as a heretic.


## Why It's Good For The Game


Sometimes people need more than just your word that their lead pipe has
been blessed by you, the most holy chaplain. That's where the purity
seals come into play, as they are a visual indicator of your deity's
approval.
<img width="259" height="182" alt="image"
src="https://github.com/user-attachments/assets/5492bae8-175a-4387-9279-263fbb492510"
/>


## Changelog
🆑
add: Added purity seals, which may be found inside two boxes being sold
by the Deus-Vend
/🆑

code/game/objects/items/storage/boxes/service_boxes.dm

@@ -294,3 +294,14 @@
 /obj/item/storage/box/heretic_box/PopulateContents()
 	for(var/i in 1 to rand(1,4))
 		new /obj/item/toy/reality_pierce(src)
+
+
+/obj/item/storage/box/purity_seal_box
+	name = "box of purity seals"
+	desc = "A box containing several blessed purity seals."
+
+/obj/item/storage/box/purity_seal_box/PopulateContents()
+	for(var/i in 1 to 4)
+		new /obj/item/sticker/purity_seal(src)
+		new /obj/item/sticker/purity_seal/purity_seal_2(src)
+