refactor: rename similar → nearby, so the code says what the section does

The section ranks on distance and is headed "Other schools nearby", but every
identifier still called it "similar" — the exact drift that leaves a later
reader trusting a name over the behaviour.

Mechanical: files, the module, the payload key, the type, the components, the
prop. No behaviour change; the suites are unchanged in count and still green.
Free to do now because #150 has not merged, so the payload key rename needs no
lockstep deploy. Uses of "similar" that are ordinary English — progress
measures compared to similar pupils, and unrelated comments — are untouched.

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

nextjs-app/components/school/SecondarySchoolSections.tsx

@@ -14,7 +14,7 @@
 import type {
   School, SchoolResult, AbsenceData, OfstedInspection, SchoolCensus,
   SchoolAdmissions, SchoolAdmissionDistance, SchoolDeprivation, SchoolFinance, NationalAverages,
-  SchoolDestinations, SimilarSchool,
+  SchoolDestinations, NearbySchool,
 } from '@/lib/types';
 import { ofstedLegacyAreas } from '@/lib/utils';
 import type { SecondaryFlags } from '@/lib/schoolSections';
@@ -27,7 +27,7 @@ import { DistanceSection } from './DistanceSection';
 import { SecondaryHistorySection } from './SecondaryHistorySection';
 import { WellbeingSection } from './WellbeingSection';
 import { FinancesSection } from './FinancesSection';
-import { SimilarSchoolsSection } from './SimilarSchoolsSection';
+import { NearbySchoolsSection } from './NearbySchoolsSection';
 import styles from './schoolSections.module.css';
 
 export interface SecondarySchoolSectionsProps {
@@ -49,14 +49,14 @@ export interface SecondarySchoolSectionsProps {
   nationalAvg: NationalAverages | null;
   destinations: SchoolDestinations | null;
   /** Nearby schools of a comparable intake. Absent on an older API build. */
-  similarSchools?: SimilarSchool[];
+  nearbySchools?: NearbySchool[];
   flags: SecondaryFlags;
 }
 
 export function SecondarySchoolSections({
   schoolInfo, yearlyData, ofsted, census,
   admissions, admissionsHistory, admissionDistance,
-  deprivation, finance, nationalAvg, destinations, similarSchools, flags,
+  deprivation, finance, nationalAvg, destinations, nearbySchools, flags,
 }: SecondarySchoolSectionsProps) {
   const secondaryAvg = nationalAvg?.secondary ?? {};
 
@@ -146,12 +146,12 @@ export function SecondarySchoolSections({
       )}
 
       {/* Last: it is where the reader goes next, not part of this school. */}
-      <SimilarSchoolsSection
+      <NearbySchoolsSection
         urn={schoolInfo.urn}
         schoolName={schoolInfo.school_name}
         phase={schoolInfo.phase}
         thisMetricValue={flags.latestResults?.attainment_8_score ?? null}
-        similar={similarSchools}
+        nearby={nearbySchools}
       />
     </div>
   );