feat(mobile): mobile cleanups for deadlines, result cards, tooltips, ofsted, rankings

MOB-07: Admissions deadlines strip becomes a horizontal snap-scroller
on ≤640px instead of a cramped 2×2 grid (which forced "Secondary ·
Deadline" track labels down to 9.6px). Cards stay readable, the right
edge fades to signal more content past the viewport, .chipTrack font
bumped to 0.7rem.

MOB-09: Result-card line3 (headline metric + secondary stats) was
crowding everything onto one row. Force the first .stat (Attainment
8 / RWM headline) to flex-basis 100% on mobile so delta-vs-LA and
pupil count wrap below it with a visible row-gap. Applied to both
SchoolRow (primary) and SecondarySchoolRow.

MOB-12: MetricTooltip ⓘ icons rendered at ~9px and relied on :hover
(which doesn't fire on touch). Hide the whole .wrapper at ≤640px —
metric labels themselves carry the meaning. Saves building a
tap-to-show layer for now.

MOB-13: The "Ofsted pending / No inspection on record" empty state
took a full hero card to communicate non-information. Add a
data-ofsted-state attribute on the hero chip; on ≤640px, the
"none" state collapses to a single muted line.

MOB-17: Already had Type+Action columns hidden on rankings mobile —
no change needed beyond marking complete.

MOB-18: Long metric headers ("Reading, Writing & Maths Combined %")
forced the value column wide. Drop .valueHeader to 0.625rem with
white-space: normal at ≤640px so labels wrap onto 2 short lines.

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

nextjs-app/components/SchoolDetailView.tsx

@@ -295,7 +295,10 @@ export function SchoolDetailView({
 
         {/* Hero signal chip strip */}
         <div className={styles.heroChips}>
-          <div className={`${styles.heroChip} ${styles[`tone-${ofstedHeroChip.tone}`]}`}>
+          <div
+            className={`${styles.heroChip} ${styles[`tone-${ofstedHeroChip.tone}`]}`}
+            data-ofsted-state={ofstedHeroChip.state}
+          >
             <div className={styles.heroChipTitle}>{ofstedHeroChip.title}</div>
             <div className={styles.heroChipSub}>{ofstedHeroChip.subtitle}</div>
             {ofstedHeroChip.detail && (