cg-shell-janitor: Clean up DSH leftover runner processes on Windows

On Windows, every dsh shell invocation launches a private runner. Although it should terminate after the command completes, it often remains idle, consuming approximately 140 MB per instance. Maintained by DonGeeo87, cg-shell-janitor (category: admin-security) samples every intervalSeconds and only terminates the runner when the parent process is a DSH host, it has no live child processes, it has not overseen background processes still running, it has been idle for more than idleMinutes, and there are no unattributable daemon orphans nearby. The plugin operates only on Windows; configuration is written in cordis.patch.yml, logs are stored in ~/.dsh/shell-janitor.log, and it is licensed under the MIT License. It is not an upstream fix but rather a heuristic cleanup solution.