Delete data/hopchain_v40_140f50k_val.parquet with huggingface_hub

Delete data/hopchain_v40_140f50k_train.parquet with huggingface_hub

Update dataset card: 28,865 rows (hopchain+vript), full schema docs

v4.0+vript combined: 2,890 val rows (739 videos), video-disjoint seed=42

v4.0+vript combined: 25,975 train rows (6,657 videos), hopchain+mixed caption

Remove old merged parquet (replaced by train/val split)

Update dataset card: 7435 rows, train/val split, full schema docs

v4.0 update: 617 val rows (150 videos), video-disjoint split seed=42

v4.0 update: 6818 train rows (1598 videos), 140f proxy paths, hopchain_v40_numeric

HopChain v4.0: 7225 keepers, hops 3-6, 5 cross-scene families, 8B-gated

initial commit