add: ShadcnUI and fix mobile layout

chore(deps): Tailwind v3->v4 and bug fixes

fix: esbuild/vite vuleratibility

fix: security vulnerabilities

fix: github actions error

add: tests

perf: SWR and optimization

test: add Playwright E2E suite, CI action, and UI performance optimization

chore: color contrast, math render

fix: math fn render

initial commit