Agent Skills: review-prs

Work the PR review queue end-to-end the Perri way — fetch the actionable queue (all buckets including dependabot), gate on CI, triage into trivial/clean/comment/discuss groups, and drive each group to a decision with explicit batch-or-individual approval. Invoke when the user says "review PRs", "let's review", "work the queue", "do PR review", or similar, or when they type /review-prs.