Going between dev and prod signs you out

We want cookies to be shared between the normal domain for the site and the staff subdomain for the site. Unfortunately, this also results in the browser trying to share cookies between khe.io, dev.khe.io, and localhost.khe.io. When you log into one version of the site, you overwrite the cookies that were created by any other version, logging you out of it. This is more of an annoyance for devs than a real problem; I'm not sure it's fixable.