amrex-codes/amrex ? reverse-engineered prompt

Build me a clean, working version of this AMReX project so I can build and run the basics on my machine.

I want it to clone, configure, and compile smoothly with CMake, and I’d like a simple example or tutorial app that shows how to use the framework for a small adaptive mesh refinement simulation. Make sure the build works with MPI by default, and keeps OpenMP and GPU support optional, since I may want to try CUDA later. If anything important is missing in the docs, please fill it in so a new user can get started without guessing.

Please also make sure the install step works, and that there’s an easy way to run a test or guided tutorial after building. If you need to check the latest usage details online, go ahead and do that.