fix(school, compare): ISI, not-yet-inspected and further-education states (H4)

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

nextjs-app/lib/compareLogic.ts

@@ -10,7 +10,8 @@
  * methodology instead of thresholding point estimates.
  */
 
-import type { OfstedInspection, SchoolAdmissions } from './types';
+import { hasReportCard } from './ofstedStatus';
+import type { OfstedInspection, School, SchoolAdmissions } from './types';
 
 // ---------------------------------------------------------------------------
 // Verdicts against an anchor (England average or state-school benchmark)
@@ -104,6 +105,16 @@ export type OfstedDisplay =
   | { kind: 'no_overall_grade' }
   | { kind: 'report_card'; summary: ReportCardSummary };
 
+/**
+ * The compare cell when a school has no Ofsted record (audit H4): ISI per GIAS,
+ * Ofsted's own "not yet inspected", or plainly that we hold nothing.
+ */
+export function noInspectionLabel(school: Pick<School, 'inspectorate' | 'ofsted_listed'>): string {
+  if (school.inspectorate === 'ISI') return 'Inspected by ISI';
+  if (school.ofsted_listed) return 'Not yet inspected';
+  return 'No inspection in our dataset';
+}
+
 export function ofstedDisplay(
   ofsted: OfstedInspection | null | undefined,
 ): OfstedDisplay {
@@ -111,7 +122,7 @@ export function ofstedDisplay(
 
   // A report card is the newest inspection format; when present it wins —
   // never derive or prefer an overall grade alongside it.
-  if (ofsted.report_card && Object.keys(ofsted.report_card).length > 0) {
+  if (hasReportCard(ofsted)) {
     return { kind: 'report_card', summary: summariseReportCard(ofsted) };
   }