PR visual guided review

A fresh agent reviews one pull request and writes one self-contained HTML page. It sees only the PR, never this session.

1. Ask which model and reasoning effort should write the review. Offer only models this runtime can launch as a fresh agent. No default.
2. Launch one fresh agent on that model with no history: the Agent tool with general-purpose in Claude Code, spawn_agent with fork_turns: "none" in Codex, or delegate_task in T3 Code. Give it only the PR URL, the path of references/writer-brief.md, and the output folder printed by node <skill-dir>/scripts/reviews.mjs path.
3. Reply with the page path, the verdict, and the finding counts.

Files

Only the writer reads these. references/writer-brief.md points to the rest: references/review-checks.md, references/diagram-types.md, assets/template.html, and assets/marks.html.