feat(seo): add school name to URLs, fix sticky nav, collapse compare widget

- URLs now /school/138267-school-name instead of /school/138267
- Bare URN URLs redirect to canonical slug (backward compat)
- Remove overflow-x:hidden that broke sticky tab nav on secondary pages
- ComparisonToast starts collapsed — user must click to open

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

nextjs-app/components/HomeView.tsx

@@ -15,6 +15,7 @@ import { EmptyState } from './EmptyState';
 import { useComparisonContext } from '@/context/ComparisonContext';
 import { fetchSchools, fetchLAaverages } from '@/lib/api';
 import type { SchoolsResponse, Filters, School } from '@/lib/types';
+import { schoolUrl } from '@/lib/utils';
 import styles from './HomeView.module.css';
 
 interface HomeViewProps {
@@ -316,7 +317,7 @@ function CompactSchoolItem({ school, onAddToCompare, isInCompare }: CompactSchoo
     <div className={styles.compactItem}>
       <div className={styles.compactItemContent}>
         <div className={styles.compactItemHeader}>
-          <a href={`/school/${school.urn}`} className={styles.compactItemName}>
+          <a href={{schoolUrl(school.urn, school.school_name)}} className={styles.compactItemName}>
             {school.school_name}
           </a>
           {school.distance !== undefined && school.distance !== null && (
@@ -352,7 +353,7 @@ function CompactSchoolItem({ school, onAddToCompare, isInCompare }: CompactSchoo
         >
           {isInCompare ? '✓ Comparing' : '+ Compare'}
         </button>
-        <a href={`/school/${school.urn}`} className="btn btn-tertiary btn-sm">
+        <a href={{schoolUrl(school.urn, school.school_name)}} className="btn btn-tertiary btn-sm">
           View
         </a>
       </div>