GetAuthenticationStateAsync (display reads: current username, nav role checks) used
to force a full revalidation + DB role re-map on every call. It now reuses the
circuit's last revalidation for NonAuthoritativeRefreshInterval (10 s);
GetAuthoritativeStateAsync (mutation gates, UI-13) still re-maps every time and
fails closed. The revocation regression test now asserts through the authoritative
read, which is what every gate uses.
Joseph Doherty