fix(compare): mobile measure-first cards to match the mockup

The grid sections (At a glance, Ofsted, Getting a place, Who goes there)
collapsed generically on mobile — grey label pills, full names wrapping
to 3 lines, no dots — making the page ~2x the mockup's height and
'significantly different' from the mobile design.

Each measure is now wrapped in a <Measure> that is display:contents on
desktop (so the label + cells still flow into the shared aligned grid,
unchanged) and a white card on mobile with compact [dot][short name]
[value] rows — matching the mobile mockup. The sticky school bar becomes
scrollable short-name pills on mobile too. Adds a shortName() util.

Desktop layout is unchanged (display:contents dissolves the wrapper).
Validated the card mechanism and real content shapes (report-card cell,
badges, %+chip rows) via static previews at both widths.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_0146VHeLAWjDVE2B5uU67jCB

nextjs-app/components/compare/sectionShared.tsx

@@ -10,7 +10,7 @@
 import type { CSSProperties, ReactNode } from 'react';
 
 import type { School } from '@/lib/types';
-import { CHART_TEXT_COLORS } from '@/lib/utils';
+import { CHART_COLORS, CHART_TEXT_COLORS, shortName } from '@/lib/utils';
 import styles from './compareSections.module.css';
 
 export function Section({
@@ -61,6 +61,29 @@ export function RowLabel({ children, tip }: { children: ReactNode; tip?: string
   );
 }
 
+/**
+ * One measure = its row label plus a cell per school. `display: contents` on
+ * desktop (see CSS) makes these flow into the section grid as if this wrapper
+ * weren't here, keeping columns aligned across measures; on mobile the wrapper
+ * becomes a card so each measure reads as its own block.
+ */
+export function Measure({
+  label,
+  tip,
+  children,
+}: {
+  label: ReactNode;
+  tip?: string;
+  children: ReactNode;
+}) {
+  return (
+    <div className={styles.measure}>
+      <RowLabel tip={tip}>{label}</RowLabel>
+      {children}
+    </div>
+  );
+}
+
 export function Cell({
   school,
   index,
@@ -73,9 +96,19 @@ export function Cell({
   return (
     <div
       className={styles.cell}
-      data-school={school.school_name}
-      style={{ '--sc': CHART_TEXT_COLORS[index % CHART_TEXT_COLORS.length] } as CSSProperties}
+      style={
+        {
+          '--sc': CHART_TEXT_COLORS[index % CHART_TEXT_COLORS.length],
+          '--dot': CHART_COLORS[index % CHART_COLORS.length],
+        } as CSSProperties
+      }
     >
+      {/* Mobile-only per-school tag (dot + short name); hidden on desktop,
+          where the column header identifies the school. */}
+      <span className={styles.cellTag}>
+        <span className={styles.cellDot} aria-hidden="true" />
+        {shortName(school.school_name)}
+      </span>
       {children}
     </div>
   );