feat(skills): add react-patterns, react-testing, react-performance
Three new skills under skills/ following the SKILL.md convention.
- react-patterns: React 18/19 idioms — hooks discipline, state
location decision tree, server/client component boundary,
Suspense + error boundaries, form actions (React 19), data
fetching matrix, composition recipes, accessibility-first.
- react-testing: React Testing Library + Vitest/Jest, query
priority order, userEvent, MSW network mocking, axe a11y
assertions, RTL vs Playwright CT boundary, TDD workflow.
- react-performance: 70-rule performance ruleset adapted from
Vercel Labs react-best-practices (MIT) across 8 priority
categories — waterfalls, bundle size, server-side, client
fetch, re-render, rendering, JS micro, advanced patterns.
Includes Lighthouse / Web Vitals mapping and attribution to
upstream.
Cross-links between the three skills and out to frontend-patterns,
accessibility, e2e-testing, tdd-workflow.
AlexisLeDain