feat(ui): add phase indicators to school list rows

Add coloured left-border and phase label pill to visually differentiate
school phases (Primary, Secondary, All-through, Post-16, Nursery) in
search result lists. Colours are accessible (WCAG AA) and don't clash
with existing Ofsted/trend semantic colours.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

nextjs-app/components/SecondarySchoolRow.tsx

@@ -11,7 +11,7 @@
 'use client';
 
 import type { School } from '@/lib/types';
-import { schoolUrl } from '@/lib/utils';
+import { getPhaseStyle, schoolUrl } from '@/lib/utils';
 import styles from './SecondarySchoolRow.module.css';
 
 const OFSTED_LABELS: Record<number, string> = {
@@ -58,6 +58,7 @@ export function SecondarySchoolRow({
     }
   };
 
+  const phase = getPhaseStyle(school.phase);
   const att8 = school.attainment_8_score ?? null;
   const laDelta =
     att8 != null && laAvgAttainment8 != null ? att8 - laAvgAttainment8 : null;
@@ -67,7 +68,7 @@ export function SecondarySchoolRow({
   const showGender = school.gender && school.gender.toLowerCase() !== 'mixed';
 
   return (
-    <div className={`${styles.row} ${isInCompare ? styles.rowInCompare : ''}`}>
+    <div className={`${styles.row} ${phase.key ? styles[`phase${phase.key}`] : ''} ${isInCompare ? styles.rowInCompare : ''}`}>
       {/* Left: four content lines */}
       <div className={styles.rowContent}>
 
@@ -90,6 +91,11 @@ export function SecondarySchoolRow({
 
         {/* Line 2: Context tags */}
         <div className={styles.line2}>
+          {phase.label && (
+            <span className={`${styles.phaseLabel} ${styles[`phaseLabel${phase.key}`]}`}>
+              {phase.label}
+            </span>
+          )}
           {school.school_type && <span>{school.school_type}</span>}
           {school.age_range && <span>{school.age_range}</span>}
           {showGender && (