For management endpoints that change server state (restart, ban, etc),
add a referer header check to safeguard against both CSRF and accidental
browser history completion.
Closes#1
10,000 hours mucking with `git filter-repo` and no reasonable use-case
found. On the plus side, anyone looking at this and curious what I nuked
isn't missing much. This lived in a monorepo up until about a week ago.
