ExcelsiorCreative/phase-viz ? reverse-engineered prompt

Build me a browser based music visualizer that lets me drop in a local audio file and watch it drive a reactive 3D scene in real time.

I want it to feel like a creative tool for musicians and VJs, with a few different visual styles to switch between, like a 3D visualizer, a waveform view, and an image effect mode. Add controls for things like particles, intensity, boost, fullscreen performance mode, and presets I can save and reuse. It should keep everything local in the browser, so no uploads are needed.

Also include a way to export the finished visual as an MP4 right in the browser, with a fast option if available and a fallback if not. Make the layout polished and modern, and make sure the app is easy to run locally with a clear dev setup. If you need to check current browser support or APIs, look up the latest docs online.