Makes trees transparent if important objects are hiding behind them (#18627)

* tree!

* Update code/modules/admin/verbs/freeze.dm

* yeet

* steel review, animate transparency

* more critical items

* charlie review

* charlie

code/modules/admin/verbs/freeze.dm

@@ -29,6 +29,8 @@ GLOBAL_LIST_EMPTY(frozen_atom_list) // A list of admin-frozen atoms.
 	var/frozen = null
 	/// Used for keeping track of previous sleeping value with admin freeze.
 	var/admin_prev_sleeping = 0
+	/// Flag to enable these making trees semi-transparent if behind them
+	flags_2 = CRITICAL_ATOM_2
 
 /mob/living/admin_Freeze(client/admin, skip_overlays = FALSE, mech = null)
 	if(!istype(admin))

code/modules/awaymissions/mission_code/beach.dm

@@ -88,6 +88,10 @@
 	heavyfootstep = FOOTSTEP_WATER
 	smoothing_groups = list(SMOOTH_GROUP_BEACH_WATER)
 
+/turf/simulated/floor/beach/away/water/Initialize(mapload)
+	. = ..()
+	RegisterSignal(src, COMSIG_ATOM_INITIALIZED_ON, .proc/InitializedOn)
+
 /turf/simulated/floor/beach/away/water/Entered(atom/movable/AM, atom/OldLoc)
 	. = ..()
 	if(!linkedcontroller)
@@ -102,7 +106,7 @@
 	if(ismob(AM))
 		linkedcontroller.mobinpool -= AM
 
-/turf/simulated/floor/beach/away/water/InitializedOn(atom/A)
+/turf/simulated/floor/beach/away/water/proc/InitializedOn(atom/A)
 	if(!linkedcontroller)
 		return
 	if(istype(A, /obj/effect/decal/cleanable)) // Better a typecheck than looping through thousands of turfs everyday

code/modules/mob/living/carbon/alien/special/facehugger.dm

@@ -16,6 +16,7 @@
 	throw_range = 5
 	tint = 3
 	flags = AIRTIGHT
+	flags_2 = CRITICAL_ATOM_2
 	flags_cover = MASKCOVERSMOUTH | MASKCOVERSEYES
 	layer = MOB_LAYER
 	max_integrity = 100

code/modules/power/supermatter/supermatter.dm

@@ -85,7 +85,7 @@
 	icon_state = "darkmatter"
 	density = TRUE
 	anchored = TRUE
-	flags_2 = RAD_PROTECT_CONTENTS_2 | RAD_NO_CONTAMINATE_2 | IMMUNE_TO_SHUTTLECRUSH_2 | NO_MALF_EFFECT_2
+	flags_2 = RAD_PROTECT_CONTENTS_2 | RAD_NO_CONTAMINATE_2 | IMMUNE_TO_SHUTTLECRUSH_2 | NO_MALF_EFFECT_2 | CRITICAL_ATOM_2
 	light_range = 4
 	resistance_flags = INDESTRUCTIBLE | LAVA_PROOF | FIRE_PROOF | UNACIDABLE | ACID_PROOF | FREEZE_PROOF
 	base_icon_state = "darkmatter"