Forensic, stage-aware pull request review. Reconstructs the commit narrative, tests architectural premises against project reality, detects over-engineering, and produces a ready-to-post review comment. Use when the user says "review PR", "review this PR", "review PR #N", "is this PR ready to merge", "review the diff", or any variation of wanting to critically evaluate a pull request for merge readiness. Do NOT use for branch summaries or "what does this PR do" questions — those are explanation tasks, not reviews.
