feat(school-detail): dedupe hero header, drop redundant chip strip

The hero header rendered the Ofsted signal twice — once as a chip in the
strip and again as a tile in the at-a-glance scorecard — and an
Oversubscribed chip already covered by the First-choice tile's footnote.

Remove the chip strip on both primary and secondary detail views, leaving
the scorecard trio (Results · Ofsted · First-choice) as the single home
for the headline numbers. Widen the scorecard's render gate to hasHeroStats
so a school with an Ofsted rating but no results still shows its Ofsted
signal (previously carried by the chip strip). Drop the now-dead .heroChip
CSS, keeping the shared .tone-* tokens the scorecard's serif number uses.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

nextjs-app/components/SecondarySchoolDetailView.module.css

@@ -702,49 +702,8 @@
     color: var(--text-primary, #1a1612);
 }
 
-/* ── Hero chips strip ────────────────────────────────── */
-.heroChips {
-    display: flex;
-    flex-wrap: wrap;
-    gap: 0.75rem;
-    margin-top: 1.25rem;
-}
-
-.heroChip {
-    flex: 0 0 240px;
-    padding: 0.75rem 1rem;
-    border-radius: 8px;
-    border-left: 3px solid var(--border-color, #e5dfd5);
-    background: var(--bg-secondary, #f3ede4);
-    color: var(--text-primary, #1a1612);
-    display: flex;
-    flex-direction: column;
-    gap: 0.15rem;
-}
-
-.heroChipTitle {
-    font-size: 0.9375rem;
-    font-weight: 700;
-    line-height: 1.3;
-    white-space: nowrap;
-    overflow: hidden;
-    text-overflow: ellipsis;
-}
-
-.heroChipSub {
-    font-size: 0.75rem;
-    color: var(--text-secondary, #5c564d);
-    line-height: 1.4;
-}
-
-.heroChipDetail {
-    font-size: 0.75rem;
-    font-weight: 600;
-    line-height: 1.4;
-    margin-top: 0.1rem;
-}
-
-/* Hero tone system */
+/* Hero tone system — colour tokens applied to the scorecard's serif Ofsted
+   number (colour only), independent of the .ofstedGrade{N} badges. */
 .tone-teal {
     --hero-tone: var(--accent-teal, #2d7d7d);
 }
@@ -761,19 +720,6 @@
     --hero-tone: var(--text-muted, #8a847a);
 }
 
-.heroChip.tone-teal,
-.heroChip.tone-green,
-.heroChip.tone-gold,
-.heroChip.tone-coral,
-.heroChip.tone-neutral {
-    border-left-color: var(--hero-tone);
-    background: color-mix(in srgb, var(--hero-tone) 10%, var(--bg-card, white));
-}
-
-.heroChip.tone-neutral {
-    background: var(--bg-secondary, #f3ede4);
-}
-
 /* ── Hero at-a-glance stats ──────────────────────────── */
 .heroStats {
     display: flex;
@@ -1170,15 +1116,6 @@
         font-size: 0.75rem;
     }
 
-    .heroChips {
-        gap: 0.5rem;
-        margin-top: 1rem;
-    }
-
-    .heroChip {
-        min-width: 100%;
-    }
-
     .heroStats {
         gap: 1rem 1.5rem;
     }