I do it in `~/.zprofile`.

Upstream's intentions are vague (IMO), but because Arch (and Fedora/Debian) puts PATH manipulation in `/etc/zsh/zprofile`, which is sourced after `~/.zshenv` (my preference), I have to do it in `~/.zprofile` or `~/.zshrc`. I chose `~/.zprofile` because I was sick of getting command-not-found errors in non-interactive settings.