Leanable component (#21431)

Refactors leanable code into a component, now attached to walls, (full)
windows, doors (of all types), and vending machines. See video for
example behavior.

https://github.com/user-attachments/assets/032d2cb2-17e3-4604-90b6-040e183dccd9

code/game/objects/structures.dm

@@ -103,28 +103,24 @@
 	return FALSE
 
 /obj/structure/mouse_drop_receive(atom/dropped, mob/user, params)
-
 	var/mob/living/H = user
 	if(istype(H) && can_climb(H) && dropped == user)
-		do_climb(dropped)
-	else
-		return ..()
+		if(!do_climb(dropped))
+			return ..()
 
 /obj/structure/proc/can_climb(var/mob/living/user, post_climb_check=0)
 	if (!climbable)
-		to_chat(user, SPAN_WARNING("\The [src] cannot be climbed!"))
 		return FALSE
 
 	if (!can_touch(user) || (!post_climb_check && (user in climbers)))
 		return FALSE
 
 	if (!user.Adjacent(src))
-		to_chat(user, SPAN_WARNING("You must be next to \the [src] to climb it."))
 		return FALSE
 
 	var/obj/occupied = turf_is_crowded()
 	if(occupied)
-		to_chat(user, SPAN_WARNING("There's \a [occupied] in the way."))
+		to_chat(user, SPAN_WARNING("There's \a [occupied] in the way of climbing this."))
 		return FALSE
 	return TRUE
 
@@ -145,7 +141,7 @@
 
 /obj/structure/proc/do_climb(var/mob/living/user)
 	if (!can_climb(user))
-		return
+		return FALSE
 
 	user.visible_message(SPAN_WARNING("[user] starts [atom_flags & ATOM_FLAG_CHECKS_BORDER ? "leaping over" : "climbing onto"] \the [src]!"))
 	LAZYADD(climbers, user)

code/game/objects/structures/window.dm

@@ -781,6 +781,10 @@
 	qdel(src)
 	update_nearby_icons()
 
+/obj/structure/window/full/mouse_drop_receive(atom/dropping, mob/user, params)
+	//Adds the component only once. We do it here & not in Initialize() because there are tons of walls & we don't want to add to their init times
+	LoadComponent(/datum/component/leanable, dropping)
+
 /********** Full Windows **********/
 // Reinforced Window
 /obj/structure/window/full/reinforced