C4illin/ConvertX ? reverse-engineered prompt

Build me a self hosted online file converter that I can run in Docker and open in the browser. I want people to be able to upload files, convert them between lots of common formats, and download the results easily. It should support converting multiple files at once, let me protect files with a password, and support user accounts so more than one person can use it safely.

Make the app feel simple and clean, with a modern interface that works well on desktop and mobile. Since this is meant to be self hosted, include the usual setup options for things like a secret key, whether registration is allowed, whether unauthenticated access is allowed, and automatic cleanup of old files. If you need current docs for any of the conversion tools or deployment details, look them up online.

I’d like the project to be ready to run locally and also easy to deploy with Docker Compose.