Snouts push masks out a bit (#94640)

## About The Pull Request

If you have a snout (and it isn't already handled elsewhere by your
species), masks will now be pushed 1 whole pixel up and away from you
when facing left or right.

Examples (TOP IS OLD, BOTTOM IS NEW)

(did you know the welding visor has the lizard's snout sticking out the
front)?

<img width="441" height="357" alt="image"
src="https://github.com/user-attachments/assets/5d703afc-2541-4789-956c-f27dc3fdcf31"
/>

I also tried moving it up one tile too, but it didn't look as nice. (To
be clear, these are not the ones being used, the above screenshot is)
(once again top row is old, bottom row is new)

<img width="1443" height="493" alt="image"
src="https://github.com/user-attachments/assets/c7193237-39fb-466b-9dcd-f5db2a646628"
/>
<img width="1138" height="490" alt="image"
src="https://github.com/user-attachments/assets/398154df-3e56-4f59-b350-24a9c9ea04a1"
/>


## Why It's Good For The Game

I think this makes masks fit snouted faces a little bit better?
Currently they sorta clip into the face which is a little bad imo.

## Changelog

🆑
add: Masks now fit snouted species a little bit better, maybe.
/🆑

code/modules/surgery/organs/external/_visual_organs.dm

@@ -163,6 +163,24 @@ Unlike normal organs, we're actually inside a persons limbs at all times
 
 	organ_flags = parent_type::organ_flags | ORGAN_EXTERNAL
 
+	/// Offset to apply to equipment worn on the mouth we give to the head.
+	var/datum/worn_feature_offset/worn_mask_offset
+
+/obj/item/organ/snout/on_bodypart_insert(obj/item/bodypart/head/limb)
+	. = ..()
+	if(isnull(limb.worn_mask_offset))
+		worn_mask_offset = limb.worn_mask_offset = new(
+			attached_part = limb,
+			feature_key = OFFSET_FACEMASK,
+			offset_x = list("east" = 1, "west" = -1),
+		)
+
+/obj/item/organ/snout/on_bodypart_remove(obj/item/bodypart/head/limb, movement_flags)
+	if(worn_mask_offset)
+		QDEL_NULL(worn_mask_offset)
+		limb.worn_mask_offset = null
+	return ..()
+
 /datum/bodypart_overlay/mutant/snout
 	layers = EXTERNAL_ADJACENT
 	feature_key = FEATURE_SNOUT