Cleanup artifacts from node build flow

web/js/app.mjs

@@ -0,0 +1,23 @@
+import {library, dom} from '@fortawesome/fontawesome-svg-core/index.es';
+import {fas} from '@fortawesome/free-solid-svg-icons/index.es';
+import {far} from '@fortawesome/free-regular-svg-icons/index.es';
+library.add(fas, far);
+
+// Old application code
+import './main.mjs';
+
+// New application code
+import Theme from './theme.mjs';
+
+document.addEventListener('DOMContentLoaded', () => {
+  Theme.init();
+
+  // Replace any existing <i> tags with <svg> and set up a MutationObserver to
+  // continue doing this as the DOM changes.
+  dom.watch();
+
+  document.getElementById('theme-switch-btn').addEventListener('click', () => {
+    Theme.swap();
+  });
+});
+