feat: Replace welcome section with NostrFeed component in Home.vue

- Remove the welcome message and user profile card to integrate the NostrFeed component for displaying announcements.

src/pages/Home.vue

@@ -2,23 +2,12 @@
   <div class="container py-8 space-y-6">
     <PWAInstallPrompt auto-show />
     <NotificationPermission auto-show />
-    
-    <!-- Welcome Section -->
-    <div class="text-center space-y-4">
-      <h1 class="text-3xl font-bold tracking-tight">Welcome back!</h1>
-      <p class="text-lg text-muted-foreground">
-        You are logged in as {{ auth.userDisplay.value?.name }}
-      </p>
-    </div>
-
-    <!-- User Profile Card -->
-    <UserProfile />
+    <NostrFeed feed-type="announcements" />
   </div>
 </template>
 
 <script setup lang="ts">
+import NostrFeed from '@/components/nostr/NostrFeed.vue'
 import NotificationPermission from '@/components/notifications/NotificationPermission.vue'
 import PWAInstallPrompt from '@/components/pwa/PWAInstallPrompt.vue'
-import UserProfile from '@/components/auth/UserProfile.vue'
-import { auth } from '@/composables/useAuth'
 </script>