All the things you describe are already being done by any team with a modern CI/CD workflow, and none of it requires AI.

At my last job, all of those steps were automated and required exactly zero human input.

Are you sure about "all"? Because I mentioned not only env deployment, but also functional issue reproduction using UI/API, which is also require necessary pre-setup.

Automated tests partially solve the case, but in real world no one writes tests blindly. It's always manual work, and when the failing trajectory is clear - the test is written.

Theoretically agent can interact with UI or API. But it requires deep project understanding, gathered from code, documentation, git history, tickets, slack. And obtaining this context, building an easily accessible knowledge base and puring only necessary parts into the agent context - is still a not solved task.

If your CI/CD process was able to fully verify a fix then it would have stopped the bug from making it to production the first time around and the Jira ticket which was handed to multiple LLMs never would have existed.