A time × frequency heatmap. Realtime scrolls an analyser; static analyses PCM; prepared renders bounded host-produced magnitudes at explicit timestamps without analyzing PCM in the face. Log frequency axis, six colour ramps, and the bin-to-pixel mapping is a pure exported function you can test or render headlessly.
pnpm dlx shadcn@latest add "https://pluginui.com/r/core-spectrogram.json"