- Add vitest, @testing-library/react, @vitest/ui, jsdom dependencies
- Create vitest.config.ts with jsdom environment and coverage settings
- Add tests/setup.ts with localStorage mock and crypto mock
- Add tests/gateway/ws-client.test.ts for GatewayClient unit tests
Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>
