Nice work! Just looking through the Eio code, you may want to use the capability restrictions more. For example, in the static file serving code, you can use `Eio.Path.open_subtree` which will use Linux fd sandboxing to prevent accidental symlink escapes or other ways to leave that subtree: https://ocaml-multicore.github.io/eio/eio/Eio/Path/index.htm...