delossify WebGPU — lossy in / MP3 or WAV out

End-to-end pipeline running in your browser: file pick → decode → Apollo (WebGPU) → 25% Hann overlap-add → sound-gambit (JS) → MP3 or WAV export.
Current v1 limits: Chrome/WebGPU path, mono or stereo audio. Browser decode normalizes inputs into Apollo's 44.1 kHz path.

WebGPU? ORT-Web? Model
init...