The previous loop only checked ownership inside the
\`server != nil && server.TaskStream != nil\` branch. A foreign online
server returned permission denied for the whole batch while foreign
offline / unknown IDs silently went into the Offline bucket — the
response-shape delta let a RoleMember enumerate other users' online
server IDs by submitting them in batches.
Drop both foreign and unknown IDs silently into the Offline bucket
(without dispatching the upgrade task) so the response is indistinguishable
across those three states.
Co-authored-by: naiba/CloudCode <hi+cloudcode@nai.ba>
