What’s a good way to include Unison code in a more traditional Git monorepo?

That depends. What are you wanting to accomplish more broadly with the integration?

I'll mention a couple things that might be relevant - you could have the git repo reference a branch or an immutable namespace hash on Unison Share. And as part of your git repo's CI, pull the Unison code and compile and/or deploy it or whatever you need to do.

There's support for webhooks on Unison Share as well, so you can do things like "open a PR to bump the dependency on the git repo whenever a new commit is pushed to branch XYZ on Unison Share".

Basically, with webhooks on GH and/or Unison Share and a bit of scripting you can set up whatever workflow you want.

Feel free to come by the Discord https://unison-lang.org/discord if you're wanting to try out Unison but not sure how best to integrate with an existing git repo.