Session F (night2): Phase 5 — records + dossier

5.1 Archetype defined on-page: one line from the archetype library under
    ARCHETYPE DNA (BOMBER — elite raw power…); expander keeps the long form.
5.2 VYNDR-on-team live: getModelAggregate team scope (migration-020 column)
    + /api/ledger/model?team= + ModelRecord mounted on the Team Hub header.
5.3 WNBA/NBA profile parity: minutes-based usage (+MIN season cell) when
    the feed carries minutes — absent beats invented.
5.4 Settings read meter: real rolling-24h usage from the SAME store the
    limiter enforces (GET /api/user/scan-meter + proxy). Metered tiers see
    'X of N reads today' + bar; unlimited tiers see nothing. Corrects the
    stale '5 scans / month' copy.
5.5 Per-tier calibration on the MODEL tab: A+/A/B/C chips with hit% at
    n>=20 PER TIER, 'building (n/20)' below — the separation between tiers
    is the proof the grades mean something.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

web/src/app/ledger/page.tsx

@@ -44,6 +44,7 @@ interface LedgerRow {
   revised_from_grade?: string | null;
 }
 
+interface TierRecord { settled: number; hits: number; misses: number; hit_pct: number | null }
 interface ModelAggregate {
   settled: number;
   hits: number;
@@ -55,6 +56,8 @@ interface ModelAggregate {
   beat_close_pct: number | null;
   pending: number;
   min_sample?: number;
+  // Session 60 (5.5) — calibration by grade tier (n≥20 rule per tier).
+  by_tier?: Record<string, TierRecord>;
 }
 
 const SPORT_COLOR: Record<string, string> = {
@@ -160,6 +163,30 @@ export default function LedgerPage() {
   );
 }
 
+const TIER_ORDER = ['A+', 'A', 'B', 'C', 'D', 'F'];
+
+/** Session 60 (5.5) — per-tier calibration: the separation between tiers is
+ *  the proof the grades mean something. A tier under n≥20 shows "building",
+ *  never a small-sample percentage. Self-hides until ANY tier is ready. */
+function TierCalibration({ agg, minSample }: { agg: ModelAggregate; minSample: number }) {
+  const tiers = agg.by_tier || {};
+  const anyReady = TIER_ORDER.some((t) => tiers[t] && tiers[t].hit_pct != null);
+  if (!anyReady) return null;
+  return (
+    <div style={{ display: 'flex', gap: 10, flexWrap: 'wrap', marginTop: 14, paddingTop: 12, borderTop: '1px solid var(--border)' }}>
+      {TIER_ORDER.filter((t) => tiers[t] && tiers[t].settled > 0).map((t) => {
+        const b = tiers[t];
+        const ready = b.hit_pct != null;
+        return (
+          <span key={t} className="mono" style={{ fontSize: 11.5, fontWeight: 700, padding: '4px 10px', borderRadius: 6, border: '1px solid var(--border-hi)', color: ready ? 'var(--text-primary)' : 'var(--text-tertiary)' }}>
+            {t}-TIER · {ready ? `${b.hits}-${b.misses} · ${b.hit_pct}%` : `building (${b.settled}/${minSample})`}
+          </span>
+        );
+      })}
+    </div>
+  );
+}
+
 function ModelHeader({ agg, minSample }: { agg: ModelAggregate; minSample: number }) {
   const ready = agg.settled >= minSample && agg.hit_pct != null;
   return (
@@ -200,6 +227,7 @@ function ModelHeader({ agg, minSample }: { agg: ModelAggregate; minSample: numbe
           </p>
         </div>
       )}
+      <TierCalibration agg={agg} minSample={minSample} />
     </div>
   );
 }