feat: add registration and authentication

frontend/src/app/layouts/AppLayout.tsx

@@ -1,7 +1,10 @@
 import { Link, NavLink, Outlet } from "react-router-dom";
+import { useAuth } from "../auth/AuthContext";
 import { AppShellFooter } from "./AppShellFooter";
 
 export function AppLayout(): JSX.Element {
+  const { user, logout } = useAuth();
+
   return (
     <div className="app-shell">
       <header className="app-shell__header">
@@ -34,6 +37,20 @@ export function AppLayout(): JSX.Element {
           >
             + Добавить
           </NavLink>
+          {user ? (
+            <button className="app-shell__link app-shell__link--button" type="button" onClick={() => void logout()}>
+              Выйти
+            </button>
+          ) : (
+            <NavLink
+              to="/login"
+              className={({ isActive }) =>
+                isActive ? "app-shell__link app-shell__link--active" : "app-shell__link"
+              }
+            >
+              Войти
+            </NavLink>
+          )}
         </nav>
       </header>
       <main className="app-shell__main">