with --preview-host (WISPCTL_PREVIEW_HOST) deploy requires a pr-<sha7> site name and a plain host before it uploads anything, finds the owner's claimed wisp subdomain through domain.getList (or takes --preview-claim), checks the 63-character label limit, and prints the preview URL. the claim is the first label of any wisp-kind domain, so it works on any base host. no claim or several claims is an error that names the fix.