Consider adding minimalistic Keychain for storing passwords

Applications like VSCode ("Code - OSS") like to store credentials there.

https://specifications.freedesktop.org/secret-service/latest/ seems to e very GNOME Keyring and KWallet centric.

### Backend (daemon)

Both would draw in way too many dependencies. But there are lightweight alternatives such as

* https://www.freshports.org/sysutils/pass-secrets/ (In FreeBSD Ports, could not use it yet due to the lack of documentation)
* https://github.com/yousefvand/secret-service (Golang, `secretserviced` tested, working)

### Frontend (GUI)

Do we need one at all?