Linux Setup

First-boot: admin user + SSH key, then harden sshd (SSH - Snippets, SSH - Mac OS).

Arch

useradd -m alice && passwd alice
usermod -aG wheel alice          # -a appends; without it the user loses every other group
EDITOR=vi visudo                 # uncomment: %wheel ALL=(ALL:ALL) ALL

Debian / Ubuntu

adduser alice                    # interactive: home + password
usermod -aG sudo alice

Copy root’s SSH key to the new user (VPS bootstrap)

rsync --archive --chown=alice:alice ~/.ssh /home/alice/