How is pause process setup in podman

[devcode11]

Context

• On system startup, even before I run any containers, I see the pause process catatonit -P running in its own user namespace.
• If I kill this process with kill -2 <pid of catatonit>, another instance of this process starts within few seconds.
• When looking at systemd units, I see all podman related units disabled (systemctl --user list-unit-files '*podman*'), except the podman-pause-<hash>.scope unit and podman-user-wait-network-online.service static unit. None of the disabled units have any logs of being run.
• The PPID of pause process shows the user instance of systemd as its parent, and it is part of the above podman-pause scope unit.
• Enabling debug logs in systemd and checking the journald logs reveal something related to D-bus - when pause process dies, "something" runs another command podman ps --all --format=json. I am guessing that somehow it starts the pause process again.
• I see some code about moving the pause process into new scope, and forking a new pause process, but not quite sure how these run on startup automatically.

Questions

• I wanted to understand where and how is this "run on system startup" set up by default?
• Where is the D-bus stuff setup to run above command or to restart the pause process automatically? If you could point to the code file, that would be very helpful.
• If the pause process needs to be run on system startup and needs to stay running at all times, why is it not setup as a systemd service?

[devcode11]

It seemed to be started by the terminal itself, not relevant to the podman or systemd