Remove 7 non-photographic submissions from livestock category

Add livestock category: 150 caption-confirmed animal photos

Remove livestock category: images don't match the label, flag was text-derived not image-derived

v2: quality-gate + VLM content filter fix (6,066 records, 7 categories, replaces prior junk-contaminated release)

Normalize crop/diagnosis, drop confidence + health_status columns

Add files using upload-large-folder tool