Set up frontend test infrastructure

Install @testing-library/react, @testing-library/jest-dom,
@testing-library/user-event, and jsdom. Configure Vitest with globals,
jsdom environment, and a setup file importing jest-dom matchers. Add a
custom render helper wrapping components with QueryClientProvider and
MemoryRouter. Exclude e2e/ from vitest. Smoke test covers
formatEvolutionMethod.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

frontend/vite.config.ts

@@ -8,6 +8,9 @@ export default defineConfig({
   plugins: [react(), tailwindcss()],
   test: {
     environment: 'jsdom',
+    globals: true,
+    setupFiles: ['./src/test/setup.ts'],
+    exclude: ['**/node_modules/**', '**/e2e/**'],
   },
   server: {
     proxy: {