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>

Initial implementation of fire show calculator ...

- Added gnexus-ui-kit as git submodule
- Created index.html with calculator UI
- Implemented formula solver for one unknown variable
- Added artist roster with role assignment
- Calculated royalties based on net amount after material costs
- Added localStorage persistence and JSON export/import
- Created docs/plan.md with project documentation

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