Clarified extreme wounds may require amputation (#21756)

Also ensured critical limbs (the torso and head) cannot be ruined like
this.

<img width="876" height="448" alt="image"
src="https://github.com/user-attachments/assets/ce6cd6c6-7130-48ff-a107-1d8b8dd70b91"
/>

code/modules/organs/internal/_internal.dm

@@ -75,7 +75,7 @@
 /obj/item/organ/internal/proc/get_scarring_results()
 	var/scar_level = get_scarring_level()
 	if(scar_level > 0.01)
-		. += "[get_wound_severity(get_scarring_level())] scarring"
+		. += "[get_wound_severity(get_scarring_level(), FALSE, FALSE)] scarring"
 
 /obj/item/organ/internal/is_usable()
 	if(robotize_type)

code/modules/organs/organ_external.dm

@@ -268,6 +268,17 @@
 /obj/item/organ/external/proc/invalidate_marking_cache()
 	cached_markings = null
 
+///If the organ requires amputation, returns TRUE. Otherwise, returns FALSE
+/obj/item/organ/external/proc/CheckNeedsAmputation()
+	var/extreme_damage = FALSE
+	if(!(brute_ratio < 100))
+		extreme_damage = TRUE
+	if(!(burn_ratio < 100))
+		extreme_damage = TRUE
+	if(extreme_damage && !(limb_flags & ORGAN_HEALS_OVERKILL))
+		return TRUE // Limb took too much damage, nothing left to heal
+	return FALSE
+
 /obj/item/organ/external/attack_self(var/mob/user)
 	if(!length(contents))
 		return ..()

code/modules/organs/subtypes/diona.dm

@@ -40,7 +40,7 @@
 	body_part = UPPER_TORSO
 	vital = TRUE
 	parent_organ = null
-	limb_flags = 0
+	limb_flags = ORGAN_HEALS_OVERKILL
 	dislocated = -1
 	joint = "structural ligament"
 	amputation_point = "branch"

code/modules/organs/subtypes/standard.dm

@@ -16,7 +16,7 @@
 	artery_name = "internal thoracic artery"
 	dislocated = -1
 	gendered_icon = 1
-	limb_flags = ORGAN_CAN_BREAK
+	limb_flags = ORGAN_CAN_BREAK | ORGAN_HEALS_OVERKILL
 	parent_organ = null
 	encased = "ribcage"
 	augment_limit = 3
@@ -240,6 +240,7 @@
 	gendered_icon = 1
 	encased = "skull"
 	augment_limit = 3
+	limb_flags = ORGAN_CAN_AMPUTATE | ORGAN_CAN_BREAK | ORGAN_CAN_MAIM | ORGAN_HEALS_OVERKILL
 	var/can_intake_reagents = 1
 
 /obj/item/organ/external/head/body_part_class()

code/modules/organs/wounds/wound.dm

@@ -177,11 +177,10 @@
 /datum/wound/proc/heal_damage(amount)
 	if(LAZYLEN(embedded_objects))
 		return amount // heal nothing
-	if(parent_organ)
-		if (damage_type == INJURY_TYPE_BURN && !(parent_organ.burn_ratio < 100))
-			return amount // We don't want to heal wounds on irreparable organs
-		else if(!(parent_organ.brute_ratio < 100))
-			return amount
+	if (parent_organ \
+	&& ((damage_type == INJURY_TYPE_BURN && !(parent_organ.burn_ratio < 100 || (parent_organ.limb_flags & ORGAN_HEALS_OVERKILL)))\
+	|| !(parent_organ.brute_ratio < 100 || (parent_organ.limb_flags & ORGAN_HEALS_OVERKILL))))
+		return amount // We don't want to heal wounds on irreparable organs
 
 	var/healed_damage = min(src.damage, amount)
 	amount -= healed_damage