add user account page and associated functionaility to support it

frontend/src/components/Navbar.css

@@ -43,6 +43,16 @@
   color: #777;
 }
 
+.navbar__user-link {
+  color: var(--color-primary);
+  text-decoration: none;
+  transition: color 0.15s ease;
+}
+
+.navbar__user-link:hover {
+  color: var(--color-primary-hover);
+}
+
 .navbar__logout {
   padding: 0.4rem 1rem;
   font-size: 1.275rem;

frontend/src/components/Navbar.jsx

@@ -35,7 +35,7 @@ export default function Navbar() {
       </div>
 
       <div className="flex flex--center gap-lg">
-        <span className="navbar__user">{currentUser.email}</span>
+        <Link to="/account" className="navbar__user navbar__user-link">{currentUser.email}</Link>
         <button onClick={logout} className="navbar__logout">
           Logout
         </button>