fix(compare): date report cards with their own inspection date, never the legacy one

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

nextjs-app/__tests__/components/CompareOfsted.test.tsx

@@ -96,6 +96,45 @@ describe('CompareOfsted', () => {
     expect(links[0]).toHaveAttribute('href', 'https://reports.ofsted.gov.uk/provider/21/1');
   });
 
+  it('dates a report card with the report-card inspection date, never the legacy date', () => {
+    const cardSchool = school(4, 'Dated Card School');
+    const cardData: Record<string, ComparisonData> = {
+      '4': {
+        school_info: cardSchool,
+        yearly_data: [],
+        ofsted: ofsted({
+          inspection_date: '2021-10-07',
+          rc_inspection_date: '2026-02-03',
+          rc_safeguarding_met: true,
+          report_card: { rc_achievement: { code: 1, label: 'Exceptional' } },
+        }),
+      },
+    };
+    render(<CompareOfsted schools={[cardSchool]} data={cardData} />);
+    expect(screen.getByText(/3 Feb 2026/)).toBeInTheDocument();
+    expect(screen.queryByText(/7 Oct 2021/)).toBeNull();
+    expect(screen.queryByText('4+ years ago')).toBeNull();
+  });
+
+  it('shows an em dash when a report card has no rc_inspection_date yet', () => {
+    const cardSchool = school(5, 'Undated Card School');
+    const cardData: Record<string, ComparisonData> = {
+      '5': {
+        school_info: cardSchool,
+        yearly_data: [],
+        ofsted: ofsted({
+          inspection_date: '2021-10-07',
+          rc_inspection_date: null,
+          rc_safeguarding_met: true,
+          report_card: { rc_achievement: { code: 1, label: 'Exceptional' } },
+        }),
+      },
+    };
+    render(<CompareOfsted schools={[cardSchool]} data={cardData} />);
+    expect(screen.getByText('—')).toBeInTheDocument();
+    expect(screen.queryByText(/7 Oct 2021/)).toBeNull();
+  });
+
   it('renders a per-measure mobile tag with the short school name', () => {
     render(<CompareOfsted schools={schools} data={data} />);
     // Each measure repeats the schools, so the short name ("Graded" from