Optimize auth initialization by using cached middleware state

- Replace API calls with cached auth state from middleware in useAuthorization
- Add fallback to session cache and watchers for auth state updates
- Change initialization from async to synchronous for better performance
- Add DuplicateNotificationBanner component

pages/dashboard/interest-list.vue

@@ -1,6 +1,9 @@
 <template>
   <div>
     <v-container fluid>
+      <!-- Duplicate notification banner for admins -->
+      <DuplicateNotificationBanner />
+      
       <!-- Header Section -->
       <v-row class="mb-4 mb-md-6">
         <v-col cols="12" md="8">