Nice project! This project, and a similar project called Monolith[0], was a bit of an inspiration for making my own single HTML file tool called Humble[1] to solve a few edges cases I was having with bundling pages (and since I wanted a TypeScript API for making page bundles).
[0] https://github.com/wabarc/cairn
[1] https://github.com/go-shiori/obelisk