averygan/reclip ? reverse-engineered prompt

I want to build a simple, self-hosted web app that lets me download videos from almost any website. The UI should be very clean and minimal, basically just a single page with a textbox. I should be able to paste a link from YouTube, TikTok, Twitter, or Instagram, and it should fetch the video's info and show me a thumbnail.

From there, I want two clear choices: download the video as an MP4 or just the audio as an MP3. If a video has different quality options, it would be great to have a little dropdown to pick the resolution I want. I'd also like to be able to paste in multiple URLs at once to fetch them all, and then have a "download all" button.

Please use Python for the backend, maybe with Flask since it's simple. The frontend should just be vanilla HTML and CSS to keep it lightweight. For the actual downloading, use yt-dlp since it supports thousands of sites. And please include a Dockerfile to make it easy to run.