Fix ESLint unused import errors in test files

Remove unused imports (waitFor, screen, render, vi, userEvent) from
test files that were causing CI lint failures.

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

frontend/src/__tests__/components/BackupModal.test.tsx

@@ -3,7 +3,7 @@
  */
 
 import { describe, it, expect, vi, beforeEach } from 'vitest';
-import { screen, waitFor } from '@testing-library/react';
+import { screen } from '@testing-library/react';
 import userEvent from '@testing-library/user-event';
 import { render } from '../utils';
 import { BackupModal } from '../../components/BackupModal';

frontend/src/__tests__/components/ContextMenu.test.tsx

@@ -3,7 +3,7 @@
  */
 
 import { describe, it, expect, vi, beforeEach } from 'vitest';
-import { screen, waitFor } from '@testing-library/react';
+import { screen } from '@testing-library/react';
 import userEvent from '@testing-library/user-event';
 import { render } from '../utils';
 import { ContextMenu } from '../../components/ContextMenu';

frontend/src/__tests__/components/Dashboard.test.tsx

@@ -5,8 +5,6 @@
  */
 
 import { describe, it, expect, beforeEach } from 'vitest';
-import { screen, waitFor } from '@testing-library/react';
-import { render } from '../utils';
 import { http, HttpResponse } from 'msw';
 import { server } from '../mocks/server';
 

frontend/src/__tests__/components/EditQueueItemModal.test.tsx

@@ -7,7 +7,7 @@
  */
 
 import { describe, it, expect, vi, beforeEach } from 'vitest';
-import { screen, waitFor } from '@testing-library/react';
+import { screen } from '@testing-library/react';
 import userEvent from '@testing-library/user-event';
 import { render } from '../utils';
 import { EditQueueItemModal } from '../../components/EditQueueItemModal';

frontend/src/__tests__/components/FileManagerModal.test.tsx

@@ -4,15 +4,13 @@
  */
 
 import { describe, it, expect, vi, beforeEach } from 'vitest';
-import { screen, waitFor } from '@testing-library/react';
-import { render } from '../utils';
 import { http, HttpResponse } from 'msw';
 import { server } from '../mocks/server';
 
 // Skip these tests as FileManagerModal component structure may differ
 describe.skip('FileManagerModal', () => {
-  const mockOnClose = vi.fn();
-  const mockOnSelect = vi.fn();
+  const _mockOnClose = vi.fn();
+  const _mockOnSelect = vi.fn();
 
   beforeEach(() => {
     vi.clearAllMocks();

frontend/src/__tests__/components/Layout.test.tsx

@@ -3,7 +3,7 @@
  */
 
 import { describe, it, expect, beforeEach } from 'vitest';
-import { screen, waitFor } from '@testing-library/react';
+import { waitFor } from '@testing-library/react';
 import { render } from '../utils';
 import { Layout } from '../../components/Layout';
 import { http, HttpResponse } from 'msw';

frontend/src/__tests__/components/UploadModal.test.tsx

@@ -3,7 +3,7 @@
  * Note: UploadModal may be integrated into other components.
  */
 
-import { describe, it, expect, vi } from 'vitest';
+import { describe, it, expect } from 'vitest';
 
 // Skip these tests as UploadModal may be integrated into FileManagerPage
 describe.skip('UploadModal', () => {

frontend/src/__tests__/pages/ArchivesPage.test.tsx

@@ -4,7 +4,6 @@
 
 import { describe, it, expect, beforeEach } from 'vitest';
 import { screen, waitFor } from '@testing-library/react';
-import userEvent from '@testing-library/user-event';
 import { render } from '../utils';
 import { ArchivesPage } from '../../pages/ArchivesPage';
 import { http, HttpResponse } from 'msw';

frontend/src/__tests__/pages/FileManagerPage.test.tsx

@@ -2,7 +2,7 @@
  * Tests for the FileManagerPage component.
  */
 
-import { describe, it, expect, vi, beforeEach } from 'vitest';
+import { describe, it, expect, beforeEach } from 'vitest';
 import { screen, waitFor } from '@testing-library/react';
 import userEvent from '@testing-library/user-event';
 import { render } from '../utils';

frontend/src/__tests__/pages/MaintenancePage.test.tsx

@@ -4,7 +4,6 @@
 
 import { describe, it, expect, beforeEach } from 'vitest';
 import { screen, waitFor } from '@testing-library/react';
-import userEvent from '@testing-library/user-event';
 import { render } from '../utils';
 import { MaintenancePage } from '../../pages/MaintenancePage';
 import { http, HttpResponse } from 'msw';

frontend/src/__tests__/pages/PrintersPage.test.tsx

@@ -4,7 +4,6 @@
 
 import { describe, it, expect, beforeEach } from 'vitest';
 import { screen, waitFor } from '@testing-library/react';
-import userEvent from '@testing-library/user-event';
 import { render } from '../utils';
 import { PrintersPage } from '../../pages/PrintersPage';
 import { http, HttpResponse } from 'msw';

frontend/src/__tests__/pages/QueuePage.test.tsx

@@ -2,7 +2,7 @@
  * Tests for the QueuePage component.
  */
 
-import { describe, it, expect, vi, beforeEach } from 'vitest';
+import { describe, it, expect, beforeEach } from 'vitest';
 import { screen, waitFor } from '@testing-library/react';
 import userEvent from '@testing-library/user-event';
 import { render } from '../utils';

frontend/src/__tests__/setup.ts

@@ -14,7 +14,7 @@ import '../i18n';
 // Setup MSW server - bypass WebSocket requests so our mock handles them
 beforeAll(() =>
   server.listen({
-    onUnhandledRequest: (request, print) => {
+    onUnhandledRequest: (request, _print) => {
       // Allow WebSocket requests to pass through to our mock
       if (request.url.includes('/ws')) {
         return;