feat(home): compact value-prop line on the mobile hero (P1.7)

Phones showed only the poetic h1 and a bare search box — no coverage,
scope, or freshness statement above the fold for the 63%-of-entries,
56%-mobile audience. One compact line ('24,000+ English schools — SATs,
GCSEs, Ofsted & admissions, side by side. Updated for 2026/27') now
replaces the hidden eyebrow + full paragraph at ≤640px, costing ~2 short
lines. Desktop copy unchanged.

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

nextjs-app/components/HomeView.tsx

@@ -267,7 +267,15 @@ export function HomeView({ initialSchools, filters, totalSchools, howItWorks, ed
             Every school in England, <em className={styles.heroEmph}>compared.</em>
           </h1>
           <p className={styles.heroDescription}>
-            <strong>24,000+ primary and secondary schools</strong> with Key Stage 2 SATs, GCSE results, Ofsted grades, progress scores and admissions data — side by side, in one place.
+            {/* Full copy for larger screens; a compact merged line (coverage +
+                freshness, standing in for the hidden eyebrow too) on phones,
+                where every line above the fold costs. */}
+            <span className={styles.heroDescriptionFull}>
+              <strong>24,000+ primary and secondary schools</strong> with Key Stage 2 SATs, GCSE results, Ofsted grades, progress scores and admissions data — side by side, in one place.
+            </span>
+            <span className={styles.heroDescriptionCompact}>
+              <strong>24,000+ English schools</strong> — SATs, GCSEs, Ofsted &amp; admissions, side by side. Updated for 2026/27.
+            </span>
           </p>
         </div>
       )}