If you want atomic commits, you need to set up your CI/CD to ensure that each intermediate commit builds and passes tests.
Most pull requests should probably be squashed to appear as a single commit in the final history. But you should have the option of leaving history intact, when you want that, and then your CI/CD should run the checks as above.
You don't need squash here, though. If your CI/CD ensures that merge commits (PRs) are atomic/build and pass tests, you can `git bisect --first-parent` to just bisect your merge commits/integration points/pull requests, without tossing the other history from the git DAG.
