One take on a seconds axis from host-prepared data only: min/max peaks on a canvas, a PreparedSpectrogramData heatmap (magma, log frequency) or both, with a Wave / Spectrum / Both toggle. Draggable, keyboard-steppable start/end and loop handles report take-normalized positions; playheads; a dimmed extension past the take end; a seconds ruler; and an overlay slot whose children read the same geometry from context. The axis latches during an overlay drag. The canvas repaints only when its peaks, colour or size change.
pnpm dlx shadcn@latest add "https://pluginui.com/r/core-sample-view.json"