fix(test): add @vitest-environment happy-dom to React UI test files

6 test files across 4 packages (auth-ui, dashboard-components,
dashboard-shell, react-auth) failed with 'document is not defined'
when run from the monorepo root because the root vitest config uses
environment: 'node'. The package-local configs set happy-dom but are
ignored when vitest is invoked from root.

Fix: Add per-file '// @vitest-environment happy-dom' annotations,
which is the recommended vitest pattern for mixed-environment monorepos.
This ensures tests work regardless of which config is loaded.

Recovers 148 tests across 6 files.

packages/auth-ui/src/__tests__/auth-ui.test.tsx

@@ -1,3 +1,4 @@
+// @vitest-environment happy-dom
 import { describe, expect, it, vi, beforeEach } from 'vitest';
 import { render, screen, fireEvent, cleanup } from '@testing-library/react';
 import { LoginForm } from '../LoginForm.js';

packages/auth-ui/src/__tests__/new-components.test.tsx

@@ -1,3 +1,4 @@
+// @vitest-environment happy-dom
 import { describe, expect, it, vi, beforeEach } from 'vitest';
 import { render, screen, fireEvent, cleanup } from '@testing-library/react';
 import { RegisterForm } from '../RegisterForm.js';

packages/dashboard-components/src/components.test.tsx

@@ -1,3 +1,4 @@
+// @vitest-environment happy-dom
 import { describe, it, expect, vi } from 'vitest';
 import { render, screen, fireEvent } from '@testing-library/react';
 import { LoadingSpinner } from './LoadingSpinner.js';

packages/dashboard-shell/src/__tests__/dashboard-shell.test.tsx

@@ -1,3 +1,4 @@
+// @vitest-environment happy-dom
 import { describe, it, expect, vi, beforeEach } from 'vitest';
 import { render, screen, fireEvent, cleanup } from '@testing-library/react';
 import { DashboardShell } from '../DashboardShell.js';

packages/react-auth/src/__tests__/react-auth.test.tsx

@@ -1,3 +1,4 @@
+// @vitest-environment happy-dom
 import { describe, expect, it, vi, beforeEach } from 'vitest';
 import { render, screen, act, cleanup } from '@testing-library/react';
 import { createAuthProvider } from '../index.js';

packages/react-auth/src/__tests__/smartauth.test.tsx

@@ -1,3 +1,4 @@
+// @vitest-environment happy-dom
 import { describe, expect, it, vi, beforeEach } from 'vitest';
 import { render, screen, act, cleanup } from '@testing-library/react';
 import { createAuthProvider } from '../index.js';