fix(ci): use next start instead of serve for Lighthouse CI

The site uses default Next.js build (.next/), not static export (out/).
serve was returning 404 for all pages.

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

Author: 2 people

.github/workflows/lighthouse.yml

@@ -33,8 +33,8 @@ jobs:
       - name: Start local server
         run: |
           cd website
-          npx serve out -l 3000 &
-          sleep 3
+          npx next start -p 3000 &
+          sleep 5
 
       - name: Run Lighthouse
         uses: treosh/lighthouse-ci-action@v12