- Change login page to use /api/auth/login/ instead of absolute URL
- Change register page to use /api/auth/register/ instead of absolute URL
- This fixes the 404 error with /auth/undefined/api/auth/login/ path
- Now uses Next.js rewrites from next.config.js correctly
- Add backend/utils.py for URL management
- Update serializers to use normalize_file_url()
- Update views to use URL utils from env vars
- Fix frontend components to use NEXT_PUBLIC_API_URL
- Add new env vars: DJANGO_BACKEND_URL, DJANGO_MEDIA_BASE_URL
- Replace all hardcoded localhost:8000 with configurable URLs
