Require independent evidence-based security reviews

When requesting correctness or security reviews, require them to be read-only and tied to the exact current worktree, with inspection of source lines and tests. Expect substantive, evidence-backed findings in a prescribed severity/output format and an explicit merge verdict. If a reviewer returns no findings or evidence, retry it with explicit instructions to provide evidence or blockers. After interruptions such as server restarts, request that in-progress background reviews resume rather than silently abandoning them.