Various improvements for usability and consistency and inclusion of PWA handling.

data/www/js/pwa.js

@@ -0,0 +1,9 @@
+(function () {
+  if (!('serviceWorker' in navigator)) return;
+
+  window.addEventListener('load', function () {
+    navigator.serviceWorker.register('/service-worker.js').catch(function (error) {
+      console.warn('PWA service worker registration failed:', error);
+    });
+  });
+})();