The dashboard auth panel only had branches for authed and awsmfa-error,
so an expired session (awsmfa prints "Not authenticated.", Authed=false,
Err="") fell through to the "checking…" spinner and appeared stuck.
Add an authChecked flag to distinguish "not yet checked" from "checked,
not authed", and render "re-auth needed" for any non-authed result.
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>