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/app/rankings/page.tsx

@@ -12,6 +12,7 @@ interface RankingsPageProps {
     metric?: string;
     local_authority?: string;
     year?: string;
+    phase?: string;
   }>;
 }
 
@@ -25,9 +26,10 @@ export const metadata: Metadata = {
 export const dynamic = 'force-dynamic';
 
 export default async function RankingsPage({ searchParams }: RankingsPageProps) {
-  const { metric: metricParam, local_authority, year: yearParam } = await searchParams;
+  const { metric: metricParam, local_authority, year: yearParam, phase: phaseParam } = await searchParams;
 
-  const metric = metricParam || 'rwm_expected_pct';
+  const phase = phaseParam || 'primary';
+  const metric = metricParam || (phase === 'secondary' ? 'attainment_8_score' : 'rwm_expected_pct');
   const year = yearParam ? parseInt(yearParam) : undefined;
 
   // Fetch rankings data with error handling
@@ -38,6 +40,7 @@ export default async function RankingsPage({ searchParams }: RankingsPageProps)
         local_authority,
         year,
         limit: 100,
+        phase,
       }),
       fetchFilters(),
       fetchMetrics(),
@@ -54,6 +57,7 @@ export default async function RankingsPage({ searchParams }: RankingsPageProps)
         selectedMetric={metric}
         selectedArea={local_authority}
         selectedYear={year}
+        selectedPhase={phase}
       />
     );
   } catch (error) {
@@ -68,6 +72,7 @@ export default async function RankingsPage({ searchParams }: RankingsPageProps)
         selectedMetric={metric}
         selectedArea={local_authority}
         selectedYear={year}
+        selectedPhase={phase}
       />
     );
   }