Something you may not know if you use the KeePassXC password manager: it lets you manage SSH keys, as well as passwords. You can choose to either store the keys directly in your KeePassXC database, or to associate a record in your KeePassXC database with an external keyfile.
It even integrates with your system's SSH agent, so you don't have to do anything extra to present the appropriate key when you try to shell in somewhere.
More info in the docs here:
https://keepassxc.org/docs/KeePassXC_UserGuide.html#_ssh_agent
