Initial level management works and can go down levels but need to rework the ecs a bit to have the concept of 'constant' information and make copying it easy.

dinkyecs.hpp

@@ -29,10 +29,20 @@ namespace DinkyECS {
     std::unordered_map<std::type_index, EntityMap> $components;
     std::unordered_map<std::type_index, std::any> $facts;
     std::unordered_map<std::type_index, EventQueue> $events;
+    std::vector<Entity> constants;
 
     Entity entity() {
       return ++entity_count;
     }
+/*
+    void clone_into(DinkyECS::World &from_world, DinkyECS::World &to_world) {
+
+    }
+
+    void update_constants(DinkyECS::World &from_world, DinkyECS::World &to_world) {
+
+    }
+    */
 
     template <typename Comp>
       EntityMap& entity_map_for() {