v3; defaults to pkgx^2; pure js rewrite #97

Job	Run time
install-pkgx (macos-latest)	6s
install-pkgx (ubuntu-latest)	20s
eval-zsh	25s
eval-bash	30s
eval-posix-sh	11s
linuxen (debian:buster-slim)	18s
multiple-apply-is-ok	1m 15s
no-dirs (/usr/local)	25s
linuxen (debian:bullseye-slim)	18s
sudo-not-required	16s
no-dirs (/usr/local/bin)	14s
linuxen (debian:bookworm-slim)	20s
sudo-required	16s
usage-as-proxy	26s
linuxen (archlinux:latest)	20s
upgrades	1m 16s
linuxen (ubuntu:focal)	20s
linuxen (ubuntu:jammy)	20s
linuxen (ubuntu:24.04)	21s
linuxen (ubuntu:24.10)	17s
linuxen (fedora:latest)	26s
	8m 40s

Provide feedback