Hot reloading for native code

It would be nice to be able to hot reload the C++ code, so we don't need to restart Unity every time we change it.

This could be helpful, maybe: https://github.com/fungos/cr

Start by reviewing how the Unity project builds and loads its native C++ code, then examine the linked cr project for possible hot-reload approaches. Define what native code changes must reload without restarting Unity and how that behavior can be demonstrated before estimating the implementation.

Written by the indexing model from the issue text.