fix: PCVE stands for Physics Counterfactual Video Editing

rename README title to PCVE-RigidBench

add GitHub repo link badge

fix: sync README timing/presence counts with actual 129 edits

Update README.md

Upload README.md with huggingface_hub

Restore 3 timed DELETE cases (126 -> 129 edits)

Drop 6 null-effect partway DELETE cases (132 -> 126 edits)

domino_chain: retime the timed DELETE to frame 24 (mid-fall)

Set task category to video-to-video

Rename to PCVE-RigidBench; document rigid-body-only scope

Add PCVE-Bench: 20 scenes, 131 physics edit tasks (benchmark data only)