Refactor scenes into separate files

scenes/index.js

@@ -0,0 +1,10 @@
+(() => {
+  const scenes = window.PhysilinksSceneDefs || [];
+  const gridDefault = scenes.find((s) => s.id === "scene-grid");
+  const defaultSceneId = gridDefault?.id || scenes[0]?.id || "scene-grid";
+
+  window.PhysilinksScenes = {
+    scenes,
+    defaultSceneId,
+  };
+})();