An always-present invariant in the TopBar chrome: the live serving triplet
(N correct · N refused · 0 wrong) aggregated across lanes from
/serving/metrics, the wrong count load-bearing — 0 in the verified token,
>0 in the contradicted token. It is a MIRROR, never a hard-coded zero:
renders a non-zero wrong honestly, and an honest 'metrics unavailable' when
the reports can't be read. Links to the Calibration route (the discipline
behind the number).
Tests: aggregate triplet + 0-wrong, non-zero-wrong-honest (not hard-coded),
metrics-unavailable-not-fake-zero. (Adds fetchServingMetrics/useServingMetrics
locally; unioned with B2 on rebase.)
