feat(ux): 8 UX improvements — simpler home, advanced filters, phase tabs, 4-line rows

1. Simpler home page: only search box on landing, no filter dropdowns
2. Advanced filters: hidden behind toggle on results page, auto-open if active
3. Per-school phase rendering: each row renders based on its own data
4. Taller 4-line rows with context line (type, age range, denomination, gender)
5. Result-scoped filters: dropdown values reflect current search results
6. Fix blank filter values: exclude empty strings and "Not applicable"
7. Rankings: Primary/Secondary phase tabs with phase-specific metrics
8. Compare: Primary/Secondary tabs with school counts and phase metrics

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

nextjs-app/components/SecondarySchoolRow.tsx

@@ -1,10 +1,11 @@
 /**
  * SecondarySchoolRow Component
- * Three-line row for secondary school search results
+ * Four-line row for secondary school search results
  *
- * Line 1: School name · School type · Ofsted badge
- * Line 2: Attainment 8 (large) · ±LA avg delta · Eng & Maths 4+ · Pupils
- * Line 3: LA name · gender tag · sixth form tag · admissions tag · distance
+ * Line 1: School name · Ofsted badge
+ * Line 2: School type · Age range · Gender · Sixth form · Admissions tag
+ * Line 3: Attainment 8 (large) · ±LA avg delta · Eng & Maths 4+ · Pupils
+ * Line 4: LA name · distance
  */
 
 'use client';
@@ -67,17 +68,14 @@ export function SecondarySchoolRow({
 
   return (
     <div className={`${styles.row} ${isInCompare ? styles.rowInCompare : ''}`}>
-      {/* Left: three content lines */}
+      {/* Left: four content lines */}
       <div className={styles.rowContent}>
 
-        {/* Line 1: School name + type + Ofsted badge */}
+        {/* Line 1: School name + Ofsted badge */}
         <div className={styles.line1}>
           <a href={`/school/${school.urn}`} className={styles.schoolName}>
             {school.school_name}
           </a>
-          {school.school_type && (
-            <span className={styles.schoolType}>{school.school_type}</span>
-          )}
           {school.ofsted_grade && (
             <span className={`${styles.ofstedBadge} ${styles[`ofsted${school.ofsted_grade}`]}`}>
               {OFSTED_LABELS[school.ofsted_grade]}
@@ -90,8 +88,25 @@ export function SecondarySchoolRow({
           )}
         </div>
 
-        {/* Line 2: KS4 stats */}
+        {/* Line 2: Context tags */}
         <div className={styles.line2}>
+          {school.school_type && <span>{school.school_type}</span>}
+          {school.age_range && <span>{school.age_range}</span>}
+          {showGender && (
+            <span className={styles.provisionTag}>{school.gender}</span>
+          )}
+          {sixthForm && (
+            <span className={styles.provisionTag}>Sixth form</span>
+          )}
+          {admissionsTag && (
+            <span className={`${styles.provisionTag} ${admissionsTag === 'Selective' ? styles.selectiveTag : ''}`}>
+              {admissionsTag}
+            </span>
+          )}
+        </div>
+
+        {/* Line 3: KS4 stats */}
+        <div className={styles.line3}>
           <span className={styles.stat}>
             <strong className={styles.statValueLarge}>
               {att8 != null ? att8.toFixed(1) : '—'}
@@ -124,22 +139,11 @@ export function SecondarySchoolRow({
           )}
         </div>
 
-        {/* Line 3: Location + tags */}
-        <div className={styles.line3}>
+        {/* Line 4: Location + distance */}
+        <div className={styles.line4}>
           {school.local_authority && (
             <span>{school.local_authority}</span>
           )}
-          {showGender && (
-            <span className={styles.provisionTag}>{school.gender}</span>
-          )}
-          {sixthForm && (
-            <span className={styles.provisionTag}>Sixth form</span>
-          )}
-          {admissionsTag && (
-            <span className={`${styles.provisionTag} ${admissionsTag === 'Selective' ? styles.selectiveTag : ''}`}>
-              {admissionsTag}
-            </span>
-          )}
           {isLocationSearch && school.distance != null && (
             <span className={styles.distanceBadge}>
               {school.distance.toFixed(1)} mi