Can we have a feature flag like fs-isolation and net-isolation for complete isolation of runtime from system? Net-isolation as it is set by environment variables can be used when used as binary and net-isolation as a feature can also be added. Fs modules and require from file system features need be enabled only if fs-isolation is not present. I could try a draft pull request for fs-isolation if you could give me some starting pointers.

Here's a link to Node permissions API: https://nodejs.org/api/permissions.html

Also would rquickjs require any changes to implement fs-isolation?