Fixed Firesuits lacking sprites for tajara and unathi. (#20777)

Fixes #15812

Firesuit sprites taken directly from Paradise Station
(ParadiseSS13/Paradise#26671). However, my own
modifications were needed for the emissive sprites, the helmet sprites,
and the atmospheric technician sprites.

### Asset Licenses
The following assets that **have not** been created by myself are
included in this PR:

| Path | Original Author | License |
| --- | --- | --- |
| icons/clothing/kit/firefighter.dmi |
[ElorgRHG](https://github.com/ElorgRHG) (Paradise Station) | CC-BY-SA
3.0 |

Author: Generalcamo

code/modules/clothing/head/hardhat.dm

@@ -65,6 +65,23 @@
 	min_pressure_protection = FIRESUIT_MIN_PRESSURE
 	heat_protection = HEAD
 
+	///Initial name of the fire helmet's emissive overlay. Will be changed based on [icon_supported_species_tags], above
+	var/initial_emissive_state = "atmos_fire_emissive"
+	///Special variable to handle the fire helmet's emissive overlay
+	var/emissive_state
+
+/obj/item/clothing/head/hardhat/atmos/get_mob_overlay(mob/living/carbon/human/H, mob_icon, mob_state, slot)
+	var/image/I = ..()
+	emissive_state = initial_emissive_state
+	if(icon_auto_adapt)
+		if(H && length(icon_supported_species_tags))
+			if(H.species.short_name in icon_supported_species_tags)
+				emissive_state = "[H.species.short_name]_[initial_emissive_state]"
+	if(slot == slot_head_str)
+		var/image/emissive_overlay = emissive_appearance(mob_icon, emissive_state, alpha = src.alpha)
+		I.AddOverlays(emissive_overlay)
+	return I
+
 /obj/item/clothing/head/hardhat/paramedic
 	name = "medical helmet"
 	desc = "A polymer helmet worn by paramedics throughout human space to protect their heads. This one comes with an attached flashlight and has green crosses on the sides."

code/modules/clothing/suits/utility.dm

@@ -35,10 +35,20 @@
 	max_heat_protection_temperature = FIRESUIT_MAX_HEAT_PROTECTION_TEMPERATURE
 	cold_protection = UPPER_TORSO | LOWER_TORSO | LEGS | FEET | ARMS | HANDS
 
+	///Initial name of the firesuit's emissive overlay. Will be changed based on [icon_supported_species_tags], above
+	var/initial_emissive_state = "firesuit_emissive"
+	///Special variable to handle the firesuit's emissive overlay
+	var/emissive_state
+
 /obj/item/clothing/suit/fire/get_mob_overlay(mob/living/carbon/human/H, mob_icon, mob_state, slot)
 	var/image/I = ..()
+	emissive_state = initial_emissive_state
+	if(icon_auto_adapt)
+		if(H && length(icon_supported_species_tags))
+			if(H.species.short_name in icon_supported_species_tags)
+				emissive_state = "[H.species.short_name]_[initial_emissive_state]"
 	if(slot == slot_wear_suit_str)
-		var/image/emissive_overlay = emissive_appearance(mob_icon, "firesuit-emissive", alpha = src.alpha)
+		var/image/emissive_overlay = emissive_appearance(mob_icon, emissive_state, alpha = src.alpha)
 		I.AddOverlays(emissive_overlay)
 	return I
 
@@ -52,13 +62,7 @@
 	sprite_sheets = list(
 		BODYTYPE_VAURCA_BULWARK = 'icons/mob/species/bulwark/fire.dmi'
 	)
-
-/obj/item/clothing/suit/fire/atmos/get_mob_overlay(mob/living/carbon/human/H, mob_icon, mob_state, slot)
-	var/image/I = ..()
-	if(slot == slot_wear_suit_str)
-		var/image/emissive_overlay = emissive_appearance(mob_icon, "atmos_firesuit-emissive", alpha = src.alpha)
-		I.AddOverlays(emissive_overlay)
-	return I
+	initial_emissive_state = "atmos_firesuit_emissive"
 
 /*
  * Bomb protection

html/changelogs/GeneralCamo - Atmos Fix.yml

@@ -0,0 +1,60 @@
+################################
+# Example Changelog File
+#
+# Note: This file, and files beginning with ".", and files that don't end in ".yml" will not be read. If you change this file, you will look really dumb.
+#
+# Your changelog will be merged with a master changelog. (New stuff added only, and only on the date entry for the day it was merged.)
+# When it is, any changes listed below will disappear.
+#
+# Valid Prefixes:
+#   bugfix
+#     - (fixes bugs)
+#   wip
+#     - (work in progress)
+#   qol
+#     - (quality of life)
+#   soundadd
+#     - (adds a sound)
+#   sounddel
+#     - (removes a sound)
+#   rscadd
+#     - (adds a feature)
+#   rscdel
+#     - (removes a feature)
+#   imageadd
+#     - (adds an image or sprite)
+#   imagedel
+#     - (removes an image or sprite)
+#   spellcheck
+#     - (fixes spelling or grammar)
+#   experiment
+#     - (experimental change)
+#   balance
+#     - (balance changes)
+#   code_imp
+#     - (misc internal code change)
+#   refactor
+#     - (refactors code)
+#   config
+#     - (makes a change to the config files)
+#   admin
+#     - (makes changes to administrator tools)
+#   server
+#     - (miscellaneous changes to server)
+#################################
+
+# Your name.
+author: GeneralCamo
+
+# Optional: Remove this file after generating master changelog.  Useful for PR changelogs that won't get used again.
+delete-after: True
+
+# Any changes you've made.  See valid prefix list above.
+# INDENT WITH TWO SPACES.  NOT TABS.  SPACES.
+# SCREW THIS UP AND IT WON'T WORK.
+# Also, this gets changed to [] after reading.  Just remove the brackets when you add new shit.
+# Please surround your changes in  double quotes ("). It works without them, but if you use certain characters it screws up compiling. The quotes will not show up in the changelog.
+changes:
+  - bugfix: "Firesuits (including Atmos Firesuits) no longer lack on-mob icons for tajara and unathi."
+  - rscadd: "Atmospheric technician fire helmets now include an emissive layer."
+  - code_imp: "Refactored the firesuit emissive code to be more generic (to potentially allow custom variants later)."