feature: sync multiple tabs using local storage

lib/frontend/index.js

@@ -1,8 +1,12 @@
 import App from './components/App.svelte'
 
 import * as stores from './stores'
+import * as services from './services'
 
 const boot = () => {
+
+  services.storageListener.register()
+
   new App({
     target: document.querySelector('#root'),
   })
@@ -10,6 +14,7 @@ const boot = () => {
   if (process.env.NODE_ENV === 'development') {
     window._fb2ical = {
       ...stores,
+      ...services,
     }
   }
 }