upodate Claude code and hf upload file

fix: remove deprecated local_dir_use_symlinks from hf_hub_download

fix: mp4v+ffmpeg faststart for Linux, cap overlay at 1280px wide

fix: call ensure_checkpoints() at startup, handle empty model list

feat: download checkpoints from HF model repo on startup

feat: pose model selector + overlay visualizer

fix: add HF Spaces YAML frontmatter to README

initial commit