lightos/credmap ? reverse-engineered prompt

Build me a simple Python command line tool called credmap that helps check whether a username, email, or password has been reused on a set of known websites.

I want to be able to run it with one credential or a file of credentials, then see which sites match and get clear output in the terminal. It should support basic options like showing more detail, choosing only certain sites, excluding some sites, using only secure sites, and sending traffic through a proxy if needed. It should also be able to list the available sites it can test against.

Please make it easy to add more sites later, since the tool should use site definitions from files. If it makes sense, include a Docker setup so I can build and run it quickly without much setup. If you need to look up current docs online to match the project behavior, go ahead.