Thank you for your answer.
This is more or less what I am trying to do. I agree that people caring about specs is a culture thing, I want to convince the VP that we need a clear workflow to work on complex features. If you had to recommend a tool, which one would it be ?
There should be only a single commit, vetted by the code review.
What happens before on a private branch (usually on a local copy of the repo) can be purged (and probably should be purged as a matter of course) if there is a worry of what might be contained in there.
The bottom line for is that the most important is to define a good process first before trying to use tooling to correct process deficiencies. A good process brings many benefits by 'forcing' good outcomes and avoid a lot of headaches.