gentoo-ebuilds/app-shells/atuin/files
..
atuin-daemon.service
atuin-daemon.socket
atuin.service
README.gentoo

Gentoo installs atuin's shell-init code under
	/usr/share/atuin/shell-init/
Therefore, instead of using, e.g., 'eval \"\$(atuin init zsh)\"' in
your .zshrc you can simply put \"source /usr/share/atuin/shell-init/zsh\"
there, which avoids the cost of forking a process.