feat: Enhance logout functionality and routing in authentication system

- Integrate `useRouter` in `UserProfile.vue` and `useAuth.ts` to manage navigation after logout.
- Update `handleLogout` in `Navbar.vue` to reflect that redirection is now handled within the `auth.logout()` function.

src/components/layout/Navbar.vue

@@ -43,6 +43,7 @@ const handleLogout = async () => {
   try {
     await auth.logout()
     isOpen.value = false
+    // The redirect is now handled in the auth.logout() function
   } catch (error) {
     console.error('Logout failed:', error)
   }