post
https://api.hopper.west.prod.govcloud.legion.picogrid.com/v3/mesh/machines//renew
Issues a fresh short-lived Nebula certificate for a mesh-only machine. Requires system admin, but system admin access alone is insufficient: only the identity that joined the machine may renew it, and any other caller (including another system admin) receives 403. Legion machines renew via /v3/federation and 404 here.