Steam-Headless/docker-steam-headless — reverse-engineered prompt

Build me a Docker based headless Steam server for game streaming on a home machine. I want it to boot into a lightweight desktop I can open in the browser with audio, start Steam automatically, and let me play games remotely through Steam Link, Moonlight, or Steam Remote Play. It should support NVIDIA, AMD, and Intel GPUs, controller input, Proton for Linux gaming, and make it easy to add other launchers like Heroic, Lutris, or EmuDeck from the desktop.

Please make storage behave sensibly so saves, settings, and anything important stay persistent, and give me an obvious place to mount a games library, like /mnt/games. I would also like a simple way to run extra startup scripts for custom apps or services. Include clear setup instructions for Docker Compose and basic server installs, plus a note for people who want to use their existing host display instead of starting a separate one. Keep it beginner friendly, and look up current docs online if you need to.