- Add tailwind.config.ts with shadcn/ui theme colors - Update globals.css with CSS variables for dark/light mode - Add utils.ts with cn() helper function - Add components.json for shadcn/ui CLI - Update postcss.config.mjs with autoprefixer - Exclude playwright config from tsconfig to fix build Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>