local conversion

site/src/layouts/Base.astro

@@ -208,6 +208,13 @@ const baseUrl = import.meta.env.BASE_URL ?? '/';
     <slot />
   </main>
 
+  <script>
+    // Register service worker for local activity storage (offline support)
+    if ('serviceWorker' in navigator) {
+      navigator.serviceWorker.register('/sw.js').catch(() => {});
+    }
+  </script>
+
   <script>
     const btn = document.getElementById('theme-toggle') as HTMLButtonElement;