v0.4.0

fix: extract makeCrossSection to avoid circular dependency

- Create src/makeCrossSection.ts with extracted function
- Update main.ts to import and re-export from new module
- Update svgExport.ts to import from makeCrossSection instead of main
- Update script-params to 0.4.1 for init() support
- Bump version to 0.4.0

Fixes esbuild bundling error in CADit code worker.