fix: make upload and fallback robust

feat: add spleeter and selected card exports

feat: add automatic sample card workflow

fix: surface api errors and coerce params

feat: show uploaded waveform and real progress

feat: add full-context reproduction and clearer controls

feat: render supervised edits into artifacts

feat: add supervised interactive editing state

feat: add hit review and streaming progress

feat: add run history and online clustering

feat: replace gradio with custom extraction web app