gmcpda-guard/docker ? reverse-engineered prompt

Build me a clean Docker based self hosted setup for the services already in this repo, including a reverse proxy, Headscale, Nginx, Snipe IT, OpenSpeedTest, and the other utility containers.

I want it to be easy to bring up and manage on a single server, with sensible defaults, clear environment files, and simple commands for starting, stopping, and updating everything. Please make sure the containers can work together without conflicts, and that the proxy routing is set up in a way that makes the services easy to reach from a browser.

If anything is unclear from the existing files, check the current docs online and fill in the gaps. Also clean up the repo so it is obvious what each service folder is for, and make the update script actually useful for pulling changes and redeploying the stack.