Phase 1b: React Query + Vitest on client

- @tanstack/react-query v5 with QueryClientProvider at app root
- client/src/api/queries.ts: query-key factory, hooks for tickets, ticket, audit,
  comments, users, CTI tree + cascade, plus full mutation set
  (create/update/delete ticket, add/delete comment, CTI CRUD, user CRUD)
- All page-level useEffect + useState fetching replaced:
  Dashboard, MyTickets, TicketDetail, NewTicket, admin/CTI, admin/Users
- Dashboard preserves 300ms debounced search via separate debouncedSearch state
- CTISelect cascades via useCategories / useTypes(categoryId) / useItems(typeId);
  dependent hooks disabled until parent selected
- vitest + @testing-library/react + jsdom; 6 client tests cover SeverityBadge + StatusBadge

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

client/src/components/StatusBadge.test.tsx

@@ -0,0 +1,15 @@
+import { describe, it, expect } from 'vitest';
+import { render, screen } from '@testing-library/react';
+import StatusBadge from './StatusBadge';
+
+describe('StatusBadge', () => {
+  it.each([
+    ['OPEN', 'Open'],
+    ['IN_PROGRESS', 'In Progress'],
+    ['RESOLVED', 'Resolved'],
+    ['CLOSED', 'Closed'],
+  ] as const)('renders %s as "%s"', (status, label) => {
+    render(<StatusBadge status={status} />);
+    expect(screen.getByText(label)).toBeInTheDocument();
+  });
+});