Each new SSH connection opens a systemd-logind session. Some systemd
versions leak closed sessions until the host refuses logins at 8192.
The connection check now opens one new login (the probe), not three.
Closes#9148
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Log the generated docker stop command and Docker version when
running locally so developers can inspect version-aware flags.
Skip logging outside local development.
Store each server's Docker version and build stop commands via
dockerStopCommand() so newer Docker uses --timeout instead of
deprecated --time/-t. Also show Docker version in server details.