Updated frontend

src/context/useAuth.js

@@ -0,0 +1,20 @@
+import { createContext, useContext } from 'react';
+
+/*
+ * The context object and its hook live here, apart from AuthContext.jsx.
+ *
+ * That split is what React Fast Refresh needs: a module that exports a
+ * component alongside non-component values cannot be hot-swapped, so every
+ * edit to the provider would remount the whole tree and drop the session you
+ * were testing with. AuthContext.jsx now exports only <AuthProvider>, and the
+ * hook everything imports lives in this plain module.
+ */
+export const AuthContext = createContext(null);
+
+export function useAuth() {
+  const context = useContext(AuthContext);
+  if (!context) {
+    throw new Error('useAuth must be used within an AuthProvider');
+  }
+  return context;
+}