Instead of keeping a list of users in an "admin" collection, shrunk now keeps a list of users with any permissions in the "users" collection. Each permission (so far only administrator and vanity url access) is denoted as its own field under "flags."
Yes, the interface looks terrible. But I just wanted to package the functionality first for testing while I switch over to SASS for better maintainability so it'll be easier to make this thing look good.