Previously the site had no favicon — browsers showed a generic tab
icon and PWA installs would have used the default. Adds:
- packages/chess/public/favicon.svg — knight on a dark rounded tile,
purpose-built for small sizes (fill-only, high contrast).
- <link rel=icon type=image/svg+xml> + apple-touch-icon wiring in
index.html so the SVG serves as the primary tab icon on every
platform (Chrome/Firefox/Safari desktop + iOS home-screen).
- theme-color (#0f172a) matching the favicon tile so mobile
browser chrome coordinates with the site's dark accent.
- meta description for search-result snippets and link previews.
