fix(list/map): badge report-card schools as Report Card, not their carried-forward grade

The search-result cards and map pins keyed report-card detection off
ofsted_framework === 'ReportCard', but the API sets ofsted_framework to the
raw event grouping ('Schools - S5'); worse, ofsted_grade (the carried-forward
legacy grade) was checked first and won. So report-card schools were badged
by their old grade — Barclay's pin/card read 'Outstanding · 2021' instead of
'Report Card · 2026'. Same root cause as the detail-page fix, different
surface.

Expose ofsted_rc_date on the list serialization (the report-card inspection
date, non-null only for report cards) and make both badge builders treat a
present rc-date as winning over any grade, using its year. Removes the dead
framework === 'ReportCard' branches.

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

nextjs-app/__tests__/lib/utils.test.ts

@@ -130,9 +130,23 @@ describe('buildOfstedListBadge', () => {
     expect(badge.cssClass).toBe('ofsted2');
   });
 
-  it('returns Report Card badge when framework is ReportCard', () => {
-    const badge = buildOfstedListBadge({ ofsted_grade: null, ofsted_date: '2025-11-01', ofsted_framework: 'ReportCard' });
-    expect(badge.label).toBe('Report Card · 2025');
+  it('returns a Report Card badge when ofsted_rc_date is present', () => {
+    const badge = buildOfstedListBadge({ ofsted_grade: null, ofsted_rc_date: '2026-02-03' });
+    expect(badge.label).toBe('Report Card · 2026');
+    expect(badge.cssClass).toBe('ofstedRc');
+  });
+
+  it('a report card wins over a carried-forward legacy grade', () => {
+    // The production bug: a report-card school (e.g. Barclay) also carries a
+    // carried-forward legacy grade (ofsted_grade), which used to win and label
+    // the pin "Outstanding · 2021" instead of "Report Card · 2026".
+    const badge = buildOfstedListBadge({
+      ofsted_grade: 1,
+      ofsted_date: '2021-10-07',
+      ofsted_framework: 'Schools - S5',
+      ofsted_rc_date: '2026-02-03',
+    });
+    expect(badge.label).toBe('Report Card · 2026');
     expect(badge.cssClass).toBe('ofstedRc');
   });