usePolled takes a cache key: it saves each answer in localStorage and starts
from the saved one, so opening the agents, alerts, builds, review runs or hives
view shows the last data at once and the refresh spinner marks the update. A
saved answer is dropped after a day, when it was saved by another build of the
UI, at log out (a new onLogout of the shared user menu) and when the gateway
ends the login (a new onSessionEnded of the session guard). Pages with an
editor (schedules, notification flows, broadcast) do not use it.
The swarm UI's user menu moves to @hive/shared and takes the whoami URL and
authelia's URL as props; the swarm UI keeps a thin wrapper, and the hive
dashboard and the per-agent page mount the same component. The dashboard's
nginx vhost proxies /api/whoami to authelia (the agent page is served from
the same vhost), and hive-c0re's state carries authelia_public_url, set from
services.hyperhive.swarm.authelia.url. The agent page shows the menu only
behind the gateway.
