feat: comprehensive testing infrastructure
- Add vitest with solid plugin, coverage, jsdom environment
- Create MSW mocks for API responses in test setup
- Add unit test for ProfessionAdminListPage
- Add Playwright accessibility and visual regression configs
- Add sample accessibility and visual tests
- Add ESLint + Prettier configs with SolidJS rules
- Update scripts: test, test:coverage, test:accessibility, test:visual
- Add .gitignore entries for coverage, test-results, playwright-report, .vitest
- Install required dev dependencies: vitest, @solidjs/testing-library, msw, eslint, prettier, typescript, @axe-core/playwright, etc.
- Create .github/workflows/ci.yml with lint, test, coverage, e2e, accessibility, visual checks
This sets up full testing pipeline for admin frontend.