Various bugfixes (#18823)

Fixes #18750, saving the lives of countless hangar technicians.
Prevents the Haneunim shuttle crash from leaving its thrusters behind.
Fixes ice exoplanet turfs being invisible.
Fixes the human mercenary helmet accidentally using the old sprites.

code/modules/overmap/exoplanets/decor/_turfs.dm

@@ -115,18 +115,6 @@
 /turf/simulated/floor/exoplanet/water/update_dirt()
 	return	// Water doesn't become dirty
 
-//Ice
-/turf/simulated/floor/exoplanet/ice
-	name = "ice"
-	icon = 'icons/turf/flooring/snow.dmi'
-	icon_state = "ice"
-
-/turf/simulated/floor/exoplanet/ice/update_icon()
-	return
-
-/turf/simulated/floor/exoplanet/ice/dark
-	icon_state = "icedark"
-
 //Snow
 /turf/simulated/floor/exoplanet/snow
 	name = "snow"

code/modules/overmap/exoplanets/decor/turfs/ice.dm

@@ -1,6 +1,6 @@
 /turf/simulated/floor/exoplanet/ice
 	name = "ice"
-	icon = 'icons/turf/smooth/snow.dmi'
+	icon = 'icons/turf/flooring/snow.dmi'
 	icon_state = "ice"
 	footprint_color = FALSE
 

code/modules/overmap/ship_weaponry/weaponry/longbow_ammo.dm

@@ -147,7 +147,9 @@
 
 /obj/item/warhead/longbow/attackby(obj/item/attacking_item, mob/user)
 	. = ..()
-	if(attacking_item.force > 10)
+	if(istype(attacking_item, /obj/item/mecha_equipment/clamp)) //loading a warhead into a mech shouldn't explode it
+		return
+	if(attacking_item.force > 10 && user.a_intent == I_HURT) //presumably you need to hit it pretty hard to actually set the thing off
 		cookoff(FALSE)
 
 /obj/item/warhead/longbow/ex_act(severity)