feat: Update Navbar to replace MessageSquare icon with Activity icon

- Import the Activity icon from lucide-vue-next and replace instances of the MessageSquare icon in the Navbar component.
- Enhance visual representation in the dropdown menu and button for the Relay Hub Status feature.

src/components/layout/Navbar.vue

@@ -6,7 +6,7 @@ import { useTheme } from '@/components/theme-provider'
 import { Button } from '@/components/ui/button'
 import { Badge } from '@/components/ui/badge'
 import { DropdownMenu, DropdownMenuContent, DropdownMenuItem, DropdownMenuSeparator, DropdownMenuTrigger } from '@/components/ui/dropdown-menu'
-import { Sun, Moon, Menu, X, User, LogOut, Ticket, Wallet, MessageSquare } from 'lucide-vue-next'
+import { Sun, Moon, Menu, X, User, LogOut, Ticket, Wallet, MessageSquare, Activity } from 'lucide-vue-next'
 import LanguageSwitcher from '@/components/LanguageSwitcher.vue'
 import LoginDialog from '@/components/auth/LoginDialog.vue'
 import ProfileDialog from '@/components/auth/ProfileDialog.vue'
@@ -150,7 +150,7 @@ const handleLogout = async () => {
                 My Tickets
               </DropdownMenuItem>
               <DropdownMenuItem @click="() => router.push('/relay-hub-status')" class="gap-2">
-                <MessageSquare class="h-4 w-4" />
+                <Activity class="h-4 w-4" />
                 Relay Hub Status
               </DropdownMenuItem>
               <DropdownMenuSeparator />
@@ -236,7 +236,7 @@ const handleLogout = async () => {
               </Button>
               <Button variant="ghost" size="sm" @click="() => router.push('/relay-hub-status')"
                 class="w-full justify-start gap-2">
-                <MessageSquare class="h-4 w-4" />
+                <Activity class="h-4 w-4" />
                 Relay Hub Status
               </Button>
               <Button variant="ghost" size="sm" @click="handleLogout"