I made your accouunt "matttest@myht.org";. Connect ssh using your key.
You can do force reboot server via sudo command.
% sudo /usr/sbin/shutdown -r now
and services control example:
% sudo systemctl status mariadb.service

You can do hacking application level by this account. Please don't do that. I trust you.

Thank you cooperate.
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安冨　伸浩 (マイサイト管理人)