toISOString() returned UTC date, causing the daily game to reset at
UTC midnight rather than local midnight. Users in UTC+ timezones
would see yesterday's completed game until the UTC date rolled over.
- Replace vanilla HTML/CSS/JS with Next.js App Router + React components
- Game logic (champion-data, game-engine, classic-mode) moved to lib/
- UI split into modular components (game-board, champion-search, guess-grid, etc.)
- Add Tailwind CSS v4 with CSS variables for theming
- Immutable state updates, fetch deduplication, next/image for CDN images
- champions.json moved from assets/ to public/