Better clean up funcs for managers.

src/scene_manager.odin

@@ -101,6 +101,13 @@ scene_render :: proc(scene: ^Scene) {
     }
 }
 
+scene_manager_quit :: proc(game: ^Game) {
+    for &scene in game.scene_stack {
+        destroy_scene(&scene)
+    }
+    delete(game.scene_stack)
+}
+
 // ------------------------------------------------------------------------------
 // UI Layout & Styling Constants
 // ------------------------------------------------------------------------------