Azsoft-jp/WF-GEN — reverse-engineered prompt

Build me a polished browser app called WaveformGen. I want users to upload one image, crop it nicely, upload an audio file like an MP3, then generate and download an MP4 video where the image is shown with a beautiful animated waveform moving to the music.

Everything should happen inside the browser, with no server upload for the media, so it feels private and fast. The page should stay responsive while the video is being created, show a smooth progress bar, and avoid memory crashes on longer audio. The final video should combine the original audio with the animated waveform visual.

Make the UI clean, modern, and easy for normal people to understand. Include language switching for English, Japanese, Korean, Chinese, and Russian. Use the existing TypeScript frontend setup, and use browser audio and video APIs for the heavy processing. Look up current docs online if you need to.