We do support Terraform via our CLI, but the integration is still a bit more primitive than some of our other integrations that are more "one click". It is definitely on our radar and we are actively exploring a tighter integration with Terraform.
We're also building on Terraform so this kind of integration would be neat! How well are GitHub Actions supported? We've been dancing with secrets there too.
We fully support GitHub Actions and have a native GitHub Action[0] that you can use to install our CLI.