fips-ui 0.13.0

Added

• Role superadmin for Web UI over the mesh: admin, plus the upcoming Node
  manager page on a node that manages other nodes. The local listener is now
  superadmin; admin keeps exactly its former rights.
• Node manager page (superadmins): a list of other fips nodes whose fips-ui
  this one reaches over the mesh, probed every 30 seconds for reachability,
  daemon and fips-ui versions, available updates, the helper version and
  whether every manager is listed as an admin there. Standby managers can be
  named for the day this node is lost (docs/fleet.md).
• Open a managed node from the Node manager: every page of this dashboard
  (peers, logs, configuration, firewall, access, upgrade, …) shown for that
  node, through this node's backend, which forwards the node's own API over
  the mesh. The sidebar says which node is open and leads back.
• Sync managers: one click makes every manager (this node and the
  standbys) an admin on a managed node, or on all nodes that lack one; nobody
  is removed or demoted there. A node told to update its fips-ui, or to
  install fips, is shown as restarting until it answers again.

Fixed

• Right after fips-ui starts, a public domain whose zone names this node by its
  npub is accepted as soon as fips-ui knows its own npub, not up to 15 seconds
  later.