Astronomy Bundle by Andreas Moeller, MIT explicitly declared in upstream package.json. Bundled current TS LocalSolarEclipse, Besselian 1900–2100 catalogue and supporting math at the recorded commit. All calculations offline. Times converted from upstream Julian dates; small differences from other ephemeris engines are expected.
Repository https://github.com/andrmoel/astronomy-bundle-js
Commit 2585cb6cf79be9caa93fff7edee88dc83490b3a2
Complete editable adaptation: all local HTML/CSS/JS files. No build required.