Fix: increase Gunicorn timeout to 120s for AI generation

The Claude API can take 30+ seconds for generating many questions,
which was exceeding the default 30s Gunicorn worker timeout.

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

Author: jsb2092

questionbank/Dockerfile

@@ -39,5 +39,5 @@ EXPOSE 8080
 HEALTHCHECK --interval=30s --timeout=30s --start-period=120s --retries=3 \
   CMD python -c "import urllib.request; urllib.request.urlopen('http://localhost:8080/health/')" || exit 1
 
-# Run migrations and gunicorn
-CMD python manage.py migrate --noinput && gunicorn config.wsgi:application --bind 0.0.0.0:$PORT
+# Run migrations and gunicorn (timeout 120s for AI generation requests)
+CMD python manage.py migrate --noinput && gunicorn config.wsgi:application --bind 0.0.0.0:$PORT --timeout 120