feat: creats frontend for the project

frontend/src/context/AuthContext.tsx

@@ -0,0 +1,72 @@
+import {
+  createContext,
+  useContext,
+  useState,
+  useEffect,
+  useCallback,
+  type ReactNode,
+} from 'react';
+import { getMe, login as apiLogin, logout as apiLogout } from '../api/auth';
+import { setOnUnauthorized } from '../api/client';
+
+interface AuthState {
+  user: { login: string } | null;
+  loading: boolean;
+  error: string | null;
+  login: (username: string, password: string) => Promise<void>;
+  logout: () => Promise<void>;
+}
+
+const AuthContext = createContext<AuthState | null>(null);
+
+export function AuthProvider({ children }: { children: ReactNode }) {
+  const [user, setUser] = useState<{ login: string } | null>(null);
+  const [loading, setLoading] = useState(true);
+  const [error, setError] = useState<string | null>(null);
+
+  const clearUser = useCallback(() => {
+    setUser(null);
+  }, []);
+
+  useEffect(() => {
+    setOnUnauthorized(clearUser);
+    getMe()
+      .then((me) => setUser({ login: me.login }))
+      .catch(() => setUser(null))
+      .finally(() => setLoading(false));
+  }, [clearUser]);
+
+  const login = useCallback(async (username: string, password: string) => {
+    setError(null);
+    try {
+      await apiLogin({ login: username, password });
+      const me = await getMe();
+      setUser({ login: me.login });
+    } catch (e: unknown) {
+      const msg =
+        e instanceof Error ? e.message : 'Ошибка входа';
+      setError(msg);
+      throw e;
+    }
+  }, []);
+
+  const logout = useCallback(async () => {
+    try {
+      await apiLogout();
+    } finally {
+      setUser(null);
+    }
+  }, []);
+
+  return (
+    <AuthContext.Provider value={{ user, loading, error, login, logout }}>
+      {children}
+    </AuthContext.Provider>
+  );
+}
+
+export function useAuth(): AuthState {
+  const ctx = useContext(AuthContext);
+  if (!ctx) throw new Error('useAuth must be used within AuthProvider');
+  return ctx;
+}