feat(hackathon): improve auth flow and UX

- Add email activation requirement for signup (no auto-login)
- Add form validation with React Hook Form and Zod on signup page
- Update callback page to handle email confirmation and password reset redirects
- Fix token format in API interceptor (use access_token)
- Fix middleware to use SessionToken for auth check
- Add infinite scroll with IntersectionObserver on browse teams page
- Replace all internal <a href> with <Link> components
- Add useInfiniteTeams hook for paginated team browsing

🤖 Generated with [Claude Code](https://claude.com/claude-code)

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

apps/hackathon/src/app/page.tsx

@@ -1,4 +1,4 @@
-import { useNavigate } from 'react-router';
+import { useNavigate, Link } from 'react-router';
 import { useState } from 'react';
 import { Button } from '@imphnen-frontend-service/ui/atoms';
 import { Icon } from '@iconify/react';
@@ -796,12 +796,12 @@ export default function HomePage() {
                   </a>
                 </li>
                 <li>
-                  <a
-                    href="/auth/signup"
+                  <Link
+                    to="/auth/signup"
                     className="hover:text-white transition-colors"
                   >
                     Daftar
-                  </a>
+                  </Link>
                 </li>
               </ul>
             </div>