feat(ui): replace card grid with row-based results and plain-language metric labels

Replace the school card grid with a scannable row list that shows 3x more
results per screen. Each row shows: school name + R,W&M % with trend,
area/type meta, and reading/writing/maths progress scores with plain-English
band labels (e.g. "above average") instead of raw numbers.

Add lib/metrics.ts as a single source of truth for plain-language metric
explanations and the progressBand() helper. Map view toggle is unchanged.

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

nextjs-app/components/HomeView.tsx

@@ -8,7 +8,7 @@
 import { useState, useEffect } from 'react';
 import { useSearchParams } from 'next/navigation';
 import { FilterBar } from './FilterBar';
-import { SchoolCard } from './SchoolCard';
+import { SchoolRow } from './SchoolRow';
 import { SchoolMap } from './SchoolMap';
 import { Pagination } from './Pagination';
 import { EmptyState } from './EmptyState';
@@ -134,8 +134,8 @@ export function HomeView({ initialSchools, filters, totalSchools }: HomeViewProp
             </h2>
             <select value={sortOrder} onChange={e => setSortOrder(e.target.value)} className={styles.sortSelect}>
               <option value="default">Sort: Relevance</option>
-              <option value="rwm_desc">Highest RWM%</option>
-              <option value="rwm_asc">Lowest RWM%</option>
+              <option value="rwm_desc">Highest R, W &amp; M %</option>
+              <option value="rwm_asc">Lowest R, W &amp; M %</option>
               {isLocationSearch && <option value="distance">Nearest first</option>}
               <option value="name_asc">Name A–Z</option>
             </select>
@@ -204,11 +204,12 @@ export function HomeView({ initialSchools, filters, totalSchools }: HomeViewProp
         ) : (
           /* List View Layout */
           <>
-            <div className={styles.grid}>
+            <div className={styles.schoolList}>
               {sortedSchools.map((school) => (
-                <SchoolCard
+                <SchoolRow
                   key={school.urn}
                   school={school}
+                  isLocationSearch={isLocationSearch}
                   onAddToCompare={addSchool}
                   onRemoveFromCompare={removeSchool}
                   isInCompare={selectedSchools.some(s => s.urn === school.urn)}