feat(admissions): add admissions guide page and homepage countdown strip

- New /admissions route with AdmissionsView client component
- Live countdowns (days until) to Primary/Secondary deadlines and Offer Days
- Step-by-step timelines for both tracks with highlighted milestone rows
- Tips section covering equal preference rule, late applications, waiting lists
- Homepage countdown strip (4 cards) between discovery chips and how-it-works
- Admissions nav link and footer link added

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

nextjs-app/components/Footer.tsx

@@ -25,6 +25,7 @@ export function Footer() {
               <li><a href="/" className={styles.link}>Search schools</a></li>
               <li><a href="/rankings" className={styles.link}>Rankings</a></li>
               <li><a href="/compare" className={styles.link}>Compare shortlist</a></li>
+              <li><a href="/admissions" className={styles.link}>Admissions guide</a></li>
             </ul>
           </div>