refactor(detail): extract sections as server components

Moves ~1,300 lines of section markup out of the two client views into
components/school/, mirroring the components/compare/ layout. Twelve section
components plus shared primitives, all server components. The only client
file is AdmissionsViewToggle, which owns the hidden/aria-pressed state and
receives both views as server-rendered children.

JSX was extracted mechanically rather than retyped, so the markup the CSS
modules depend on is verbatim.

Sharing follows measured similarity, not assumption:
- Finances (91%) shared. The secondary premises-cost card is gated behind a
  prop so primary pages are unchanged; enabling it is a one-line follow-up.
- Ofsted (80%) shared, but behind a variant prop. The headline similarity hid
  a real fork: on a school with no overall grade the primary page shows a
  "Not rated" badge while the secondary shows a four-area OEIF panel, and the
  disclaimer copy differs. Both preserved exactly; reconciling them is a
  human decision, not a side effect of a move.
- Admissions (14%) and History (40%) kept separate.

Not yet wired up -- the old views still render.

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

nextjs-app/components/school/SchoolLifeSection.tsx

@@ -0,0 +1,51 @@
+/**
+ * SchoolLifeSection — absence figures. Primary pages only; the secondary page
+ * carries the equivalent content inside WellbeingSection.
+ *
+ * Server component.
+ */
+
+import type { AbsenceData } from '@/lib/types';
+import { formatPercentage } from '@/lib/utils';
+import { MetricTooltip } from '../MetricTooltip';
+import { Section, sectionStyles as styles } from './sectionShared';
+
+export function SchoolLifeSection({
+  absenceData,
+  primaryAvg,
+}: {
+  absenceData: AbsenceData | null;
+  primaryAvg: Record<string, number>;
+}) {
+  return (
+    <Section id="school-life">
+      <h2 className={styles.sectionTitle}>School Life</h2>
+      <div className={styles.metricsGrid}>
+        {absenceData?.overall_absence_rate != null && (
+          <div className={styles.metricCard}>
+            <div className={styles.metricLabel}>
+              Days missed (overall absence)
+              <MetricTooltip metricKey="overall_absence_pct" />
+            </div>
+            <div className={styles.metricValue}>{formatPercentage(absenceData.overall_absence_rate)}</div>
+            {primaryAvg.overall_absence_pct != null && (
+              <div className={styles.metricHint}>England avg: ~{primaryAvg.overall_absence_pct.toFixed(1)}%</div>
+            )}
+          </div>
+        )}
+        {absenceData?.persistent_absence_rate != null && (
+          <div className={styles.metricCard}>
+            <div className={styles.metricLabel}>
+              Regularly missing school
+              <MetricTooltip metricKey="persistent_absence_pct" />
+            </div>
+            <div className={styles.metricValue}>{formatPercentage(absenceData.persistent_absence_rate)}</div>
+            {primaryAvg.persistent_absence_pct != null && (
+              <div className={styles.metricHint}>England avg: ~{primaryAvg.persistent_absence_pct.toFixed(0)}%</div>
+            )}
+          </div>
+        )}
+      </div>
+    </Section>
+  );
+}