Some stealth box changes (#45332)

About The Pull Request

Table of contents:
You can no longer deploy the box while you are inside of something. Fixes #45288
The box should no longer get hard deleted when someone else opens it.
The box now alerts people to you, even if you are the one who opened it.
Why It's Good For The Game

First one is obvious, exploit bad. You should just teleport out of mechs and welded lockers.
Second one also obvious.
Third one is because I did that on accident while testing and found it very flavourful. Feels a lot more like a sneak box if you always get the reveal animation with the red exclamation mark.
Changelog

cl
fix: You can no longer activate the stealth implant while inside of other objects.
balance: Leaving the stealth box always alerts nearby players.
/cl

code/datums/action.dm

@@ -506,6 +506,7 @@
 		else
 			to_chat(owner, "<span class='warning'>Your hands are full!</span>")
 
+///MGS BOX!
 /datum/action/item_action/agent_box
 	name = "Deploy Box"
 	desc = "Find inner peace, here, in the box."
@@ -513,22 +514,30 @@
 	background_icon_state = "bg_agent"
 	icon_icon = 'icons/mob/actions/actions_items.dmi'
 	button_icon_state = "deploy_box"
+	///Cooldown between deploys. Uses world.time
 	var/cooldown = 0
-	var/obj/structure/closet/cardboard/agent/box
+	///The type of closet this action spawns.
+	var/boxtype = /obj/structure/closet/cardboard/agent
 
+///Handles opening and closing the box.
 /datum/action/item_action/agent_box/Trigger()
-	if(!..())
+	. = ..()
+	if(!.)
 		return FALSE
-	if(QDELETED(box))
-		if(cooldown < world.time - 100)
-			box = new(owner.drop_location())
-			owner.forceMove(box)
-			cooldown = world.time
-			owner.playsound_local(box, 'sound/misc/box_deploy.ogg', 50, TRUE)
-	else
-		owner.forceMove(box.drop_location())
+	if(istype(owner.loc, /obj/structure/closet/cardboard/agent))
+		var/obj/structure/closet/cardboard/agent/box = owner.loc
+		owner.playsound_local(box, 'sound/misc/box_deploy.ogg', 50, TRUE)
+		box.open()
+		return
+	//Box closing from here on out.
+	if(!isturf(owner.loc)) //Don't let the player use this to escape mechs/welded closets.
+		to_chat(owner, "<span class = 'notice'>You need more space to activate this implant.</span>")
+		return
+	if(cooldown < world.time - 100)
+		var/box = new boxtype(owner.drop_location())
+		owner.forceMove(box)
+		cooldown = world.time
 		owner.playsound_local(box, 'sound/misc/box_deploy.ogg', 50, TRUE)
-		QDEL_NULL(box)
 
 //Preset for spells
 /datum/action/spell_action