snail007/goproxy ? reverse-engineered prompt

Build me a high performance proxy server in Go that can run as HTTP, HTTPS, SOCKS5, websocket, TCP, and UDP proxy all in one. I want it to support chaining through upstream proxies, transparent forwarding, NAT and port forwarding, SSH forwarding, and a simple way to turn on encryption for traffic between proxy hops. It should also handle domain black and white lists, client authentication, connection limits, speed limits, load balancing across multiple upstreams, and a smart mode that can decide when to go direct and when to use the upstream proxy.

Please make it easy to run from the command line with a clear config file, and include sensible defaults plus example configs so I can test it quickly on Linux or Windows. If you need to check current Go docs or proxy behavior details, look them up online. Also make sure the code is organized cleanly and the main entry point can start the different proxy modes without me having to understand the internals.