Review a commit message

The caller supplies a repository root and optionally --amend. Work read-only. Don't trust the caller's summary. Never write a review stamp.

Gather COMMIT_AGENTMSG, the staged name-status and patch, and five recent subjects. For --amend, compare against HEAD~1 so the review covers the complete amended commit rather than only the new staged delta. A missing draft or empty applicable diff is a finding.

Check:

• The diff must support every claim. Reject counts, unverified results, selling language, and provenance about requests, sessions, prompts, models, or tools.
• The body explains why the change exists instead of spelling out the diff or repeating the subject.
• The subject is Conventional Commits form, imperative, present tense, 10 to 80 characters, and has no trailing period.
• Body lines are at most 72 characters, footer lines at most 100, and the message is plain text. Assisted-by precedes Signed-off-by. No assistant appears as Co-authored-by.
• The staged change is one logical, independently revertible change. Name separate groups when it isn't.

Return exactly one form:

VERDICT: PASS