Windows used to have HTA applications, html files with a different extension that opened in a browser without menus and had access to filesystem APIs over javascript (jscript). It was probably a security nightmare, but I could see a modern version of that built on electron. Access to a folder and a sqlite db would be enough.

There's also Orca for building sandboxed wasm apps but it removes the browser and the Dom and only gives you a canvas to work with.