Attaching to the server console

Currently, there is no possibility to attach to the console. Normally admins create server processes over GNU screen session which is a very bad idea (as there is no true process management then).

The idea is to run server in a systems unit providing a TTY for the process in a way one another process could communicate bi-directly with the server service. Some helper URLs:

- https://stackoverflow.com/questions/40812634/send-stdout-stderr-to-console-for-a-systemd-service
- https://www.freedesktop.org/software/systemd/man/systemd.exec.html
- https://unix.stackexchange.com/questions/428474/attach-to-tty-running-a-process
- https://technostuff.blogspot.com/2008/10/some-useful-socat-commands.html
- https://www.linux.com/news/socat-general-bidirectional-pipe-handler/
- https://unix.stackexchange.com/questions/179827/is-it-possible-to-open-a-terminal-with-specified-tty-pty
- or via tmux?
- https://unix.stackexchange.com/questions/423334/reading-writing-to-tty-using-systemd