I built a deterministic CI firewall for AI-generated pull requests

AI coding agents are getting good enough to open pull requests. That is useful. It also changes the review problem. A normal code review asks: Does this code look correct? An AI-generated PR also raises a different question: Did this agent change something I did not intend, and does this PR have enough evidence to merge? Agent Gate is still a prerelease, so I am starting with a narrow goal: make AI-generated PRs easier to inspect before merge. That second question is why I built Agen...