feat: add admin interface for viewing and managing contact messages, including a new service and sidebar navigation.

src/components/Sidebar.tsx

@@ -91,6 +91,20 @@ const menuItems = [
       </svg>
     ),
   },
+  {
+    name: 'Contact Messages',
+    href: '/dashboard/contact-messages',
+    icon: (
+      <svg className="w-5 h-5" fill="none" stroke="currentColor" viewBox="0 0 24 24">
+        <path
+          strokeLinecap="round"
+          strokeLinejoin="round"
+          strokeWidth={2}
+          d="M3 8l7.89 5.26a2 2 0 002.22 0L21 8M5 19h14a2 2 0 002-2V7a2 2 0 00-2-2H5a2 2 0 00-2 2v10a2 2 0 002 2z"
+        />
+      </svg>
+    ),
+  },
   {
     name: 'User Reports',
     href: '/dashboard/reports',