Nex-Core-69/nex-rbg ? reverse-engineered prompt

Build me a clean web app that removes image backgrounds really fast.

I want users to upload a photo, see a live preview, and get the background removed in a couple seconds using multiple API keys so it stays quick and can switch keys when one is busy. Make the UI modern, dark blue, and simple to use on desktop and mobile. The page should let people drag and drop or pick an image, show the original and the cutout, and give them one click to download the result as a PNG.

Use a small Node server so the upload and API handling happen on the backend, and keep the setup easy with a config file for the API keys. If you need to look up the current docs online, feel free to do that. Also make sure the app looks polished, works smoothly, and is ready to run locally right away.