This is a one-sentence horror story. I almost can't believe someone would let this happen, unless the 1Password account is not important (highly unlikely).
The nice thing is that using the private key requires physical touch. That means that AI itself (or a remote attacker, for that matter) can't do things unless I confirm.
In my thinking, this is more secure than plaintext in filesystem
you know most tools like gcloud, bitwarden, etc store auth keys just in dotfiles too?
Local compromise is KO now, and we can't do shit on platforms like MacOs didn't research Linux recently