Make project work standalone without local server ...

- Copied fonts to assets/fonts/ with relative paths
- Copied kit.css to css/kit.css with fixed relative font paths
- Embedded artists JSON directly in index.html
- Updated app.js to use window.__ARTISTS__ instead of fetch
- Updated all asset paths in index.html to be relative

This allows opening index.html directly via file:// protocol.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>