fixes bugs with observer crew monitor (#24828)

code/modules/tgui/modules/crew_monitor.dm

@@ -70,8 +70,8 @@
 
 	data["is_advanced"] = is_advanced
 	data["possible_levels"] = list()
-	for(var/z in 1 to world.maxz)
-		data["possible_levels"] |= z
+	for(var/zl in GLOB.space_manager.z_list)
+		data["possible_levels"] |= zl
 
 	return data
 
@@ -79,3 +79,6 @@
 	name = "Crew monitor (Observer)"
 	is_advanced = TRUE
 	ignore_sensors = TRUE
+
+/datum/ui_module/crew_monitor/ghost/ui_state(mob/user)
+	return GLOB.observer_state