Adds `hyperframes remove-background` — a local-AI subcommand that mattes a
video or image with the u2net_human_seg ONNX model and emits a transparent
WebM (VP9-alpha), ProRes 4444 .mov, or RGBA PNG. Drops directly into any
composition's <video> tag — no green screen, no API keys, no upload.
Auto-picks the fastest available execution provider via onnxruntime-node:
CoreML on Apple Silicon, CUDA when HYPERFRAMES_CUDA=1, CPU otherwise.
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
