sagernet/sing-box ? reverse-engineered prompt

Build me a universal proxy app called sing box that can run on desktop or server and make it easy to route internet traffic through different proxy types.

I want a clean command line tool and background service that can read a config file, start and stop reliably, handle DNS and routing rules, and let me choose which traffic goes through the proxy and which does not. It should support common proxy and tunneling setups, have sensible logs, and be easy to extend later if I add new protocols or transports.

Please make it production ready, with good defaults, clear error messages, and enough documentation so someone can get it working without being an expert. If you need current reference details, look up the latest docs online first.