Add sw register

frontend/src/routes/+layout.svelte

@@ -1,7 +1,23 @@
 <script>
     import { pwaInfo } from 'virtual:pwa-info'; 
+	import { onMount } from 'svelte'
 	import BottomAppBar from '$lib/components/BottomAppBar.svelte';
 	$: webManifestLink = pwaInfo ? pwaInfo.webManifest.linkTag : '' 
+  
+  onMount(async () => {
+    if (pwaInfo) {
+      const { registerSW } = await import('virtual:pwa-register')
+      registerSW({
+        immediate: true,
+        onRegistered(r) {
+          console.log(`SW Registered: ${r}`)
+        },
+        onRegisterError(error) {
+          console.log('SW registration error', error)
+        }
+      })
+    }
+  })
 </script> 
 
 <slot></slot>