drogonframework/drogon ? reverse-engineered prompt

Build me a small C++ web server project using Drogon.

I want a clean starter app that runs from a simple config file, listens on a port, and has a few example routes to show how to do a normal web app and a JSON API. Please include one homepage route that returns simple HTML, one REST style route that returns JSON, and one route that accepts an id in the URL and returns details for that item.

Also add a basic login or auth filter example, a WebSocket example, and one upload or download endpoint so I can see how those pieces work. If it makes sense, show how to organize controllers separately instead of putting everything in main.

Use the usual Drogon style, keep the main file very small, and make it easy to run locally. If you need current setup details from the docs, look them up online first.