Add CI/testing

seems like terraform provides both unit and end-to-end testing https://www.hashicorp.com/blog/testing-hashicorp-terraform

i think we need something like this

Start by reading the linked HashiCorp article to understand the proposed Terraform unit and end-to-end testing approaches. Then inspect the repository's current CI and Terraform setup, which the issue does not identify. Done means agreeing on a concrete testing scope and adding the selected CI-integrated tests.

Written by the indexing model from the issue text.