Make the belly Visibility pref a client one as opposed to a per-character one. (#17375)

* Automatic changelog compile [ci skip]

* Make Belly pref global as opposed to per-character

---------

Co-authored-by: vorestation-ci[bot] <199609141+vorestation-ci[bot]@users.noreply.github.com>

code/modules/mob/living/carbon/human/human_helpers.dm

@@ -197,7 +197,7 @@
 	if(vantag_hud)
 		compiled_vis |= VIS_CH_VANTAG
 
-	if(stomach_vision)
+	if(client?.prefs.read_preference(/datum/preference/toggle/tummy_sprites))
 		compiled_vis += VIS_CH_STOMACH
 
 	if(soulgem?.flag_check(SOULGEM_SEE_SR_SOULS))

code/modules/mob/living/carbon/human/update_icons.dm

@@ -1112,7 +1112,6 @@ var/global/list/damage_icon_parts = list() //see UpdateDamageIcon()
 
 	var/image/wing_image = get_wing_image(FALSE)
 
-	var/obj/item/organ/external/chest = organs_by_name[BP_TORSO]
 
 	if(wing_image)
 		wing_image.layer = BODY_LAYER+WING_LAYER

code/modules/mob/mob_defines_vr.dm

@@ -1,6 +1,5 @@
 /mob
 	var/vantag_hud = 0			// Do I have the HUD enabled?
-	var/stomach_vision = 1		// By default, you will see stomachs.
 	var/mob/temporary_form		// For holding onto a temporary form
 
 	var/disconnect_time = null		//Time of client loss, set by Logout(), for timekeeping

code/modules/mob/mob_helpers_vr.dm

@@ -3,7 +3,7 @@
 
 	if(!plane_holder || !vis_enabled)
 		return
-
+	var/stomach_vision = client?.prefs.read_preference(/datum/preference/toggle/tummy_sprites)
 	if(stomach_vision && !(VIS_CH_STOMACH in vis_enabled))
 		plane_holder.set_vis(VIS_CH_STOMACH,TRUE)
 		vis_enabled += VIS_CH_STOMACH
@@ -40,10 +40,10 @@
 	if(!toggle)
 		return
 	if(toggle =="Yes")
-		stomach_vision = 1 //Simple! Easy!
+		client?.prefs.write_preference_by_type(/datum/preference/toggle/tummy_sprites,TRUE) //Simple! Easy!
 		to_chat(src, "You can now see stomachs!")
 	else
-		stomach_vision = 0
+		client?.prefs.write_preference_by_type(/datum/preference/toggle/tummy_sprites,FALSE)
 		to_chat(src, "You will no longer see stomachs!")
 	recalculate_vis()