chore: import upstream snapshot with attribution

client/vitest-setup.js

@@ -0,0 +1,13 @@
+import { vi, afterEach } from 'vitest';
+import '@testing-library/jest-dom/vitest';
+import { cleanup } from '@testing-library/react';
+
+vi.mock('react-spinkit');
+vi.mock('gatsby');
+vi.mock('react-i18next');
+
+afterEach(() => {
+  // Vitest doesn't automatically call cleanup. Without it the rendered
+  // components are never removed and so tests are not independent.
+  cleanup();
+});