BAPI - mapmanip submap weight (#23069)

changes:
  - rscadd: "Bapi mapmanip submap weight."

---------

Co-authored-by: DreamySkrell <>
Co-authored-by: AuroraBuildBot <action@github.com>

code/modules/effects/map_effects/marker/mapmanip.dm

@@ -5,6 +5,22 @@
 	icon_state = "mapmanip_extract"
 	pixel_x = -32
 	pixel_y = -32
+	/// If set, it allows extract markers to have a shared name, even across submap operations,
+	/// eliminating submaps with the same name from the selection pool.
+	/// If null, ignored.
+	///
+	/// Must be set in map, as mapmanip does not read code.
+	var/singleton_id = null
+	/// The higher the weight, the more likely the marker is to be selected.
+	/// Default is 1 if unset.
+	/// Weight must be 0 or positive.
+	///
+	/// If specifically set to 0, the marker will never be selected,
+	/// unless, and only if, all the remaining markers have a weight of 0.
+	/// Or in other words, it'll be selected last.
+	///
+	/// Must be set in map, as mapmanip does not read code.
+	var/weight = 1
 
 /obj/effect/map_effect/marker/mapmanip/submap/insert
 	name = "mapmanip marker, insert submap"