Mapleeeeeeeeeee/bilingualsub — reverse-engineered prompt

Build me a simple web app that turns a YouTube video into bilingual subtitles.

I want a page where I can paste a YouTube link, start a job, and watch the progress update live while it downloads the video, extracts the audio, transcribes the speech, translates it, and generates dual language subtitles. It should produce both SRT and ASS subtitle files, and it should also let me optionally create a version of the video with the subtitles burned in.

Please make the UI clean and easy for a normal person to use, with support for both English and Traditional Chinese. When a job finishes, I should be able to download the subtitle files and the burned in video if I chose that option. If something fails, show a clear error message.

Use a backend and frontend setup that runs locally, and make the recommended Docker run path work too. Assume transcription uses Groq Whisper and translation uses an LLM with sensible defaults from env vars. Look up current docs online if you need to.