- Add _extract_photos() helper to handle both list and dict formats
- _build_photo_urls() now skips non-dict entries gracefully
- Fallback to detail.main_photo when no photos array is present
- Add photos_count to payload for easy verification
- Add crawler warning log when a listing has zero photos after normalization
- Prefer detail photos (usually higher quality), fallback to catalog

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