Extract engine setup

index.html

@@ -106,6 +106,7 @@
         <script src="./src/scenes/scene-stack-blocks.js"></script>
         <script src="./src/scenes/index.js"></script>
         <script src="./src/config.js"></script>
+        <script src="./src/engine.js"></script>
         <script src="./src/scene-registry.js"></script>
         <script src="./src/ui.js"></script>
         <script src="./src/storage.js"></script>