Arch Linux (pacman)

Installs everything in pacman-packages.txt (official repo only — AUR packages are not installed by install.sh). neovim/nvm/pyenv come from their upstream installers (same as apt); lazygit/topgrade are pacman-installed when present in Arch's repos and fall back to an upstream tarball (lazygit) or pipx (topgrade) otherwise; zsh is pacman-installed (it isn't missing from Arch's repo). GUI apps live in pacman-packages-desktop.txt (same want_desktop_packages gate). Signal is an AUR package, so it isn't installed at all on Arch — install it yourself.