I've found various solutions to cache SSH key passphrases using such methods as
gpg-agent and so on. They all seem to cache it per-login or per-session, so that every time you reboot your computer, you will have to re-enter your passphrase to SSH (but subsequent SSHs won't ask for the password until you reboot).
I don't want the cache to clear on reboot. I want to enter the passphrase once, and never be asked for it again, even if I turn off my computer. How can I do this?
In case it matters, I'm on Manjaro.