Rules a reviewer (human or bot) must enforce on every PR to this repo. These complement CLAUDE.md (which governs src/ ↔ SPECS.md consistency) and apply to the diff itself.
Reject any PR that adds files which are local agent state, scratch notes, or per-developer tooling config. A file qualifies as an artifact when all of the following are true:
- It is generated or maintained by an AI assistant, IDE plugin, or other per-developer tool — not authored as a deliverable.
- It is not consumed by the build, the tests, the published package, or another contributor's workflow.
- It would differ machine-to-machine or session-to-session if a different contributor produced the same change.
Reviewer action: comment "remove agent artifacts (see REVIEW.md §1)" and request changes. Do not merge until the offending paths are deleted from the diff. If the author needs them tracked locally, they belong in .gitignore, not in the repo.
Why: these files capture one developer's local session — they have no value to other contributors, leak internal workflow noise into git history, and inflate review surface.
A PR titled "Convert to functional component" should only touch files needed for that conversion. If unrelated commits sneak in (tooling, notes, drive-by fixes in unrelated files), ask the author to split them into a separate PR.
See CLAUDE.md for the full contract. Summary: any change to observable behavior in src/ must either preserve the contract documented in SPECS.md or update SPECS.md in the same PR.
If a conditional has a clause that needs a multi-line comment to justify it, the clause is probably dead — drop it and the comment goes too. Common shape: x != null && Number.isFinite(x) (the null check is redundant; Number.isFinite already excludes null/undefined/Infinity). Stale narrowing workarounds (!= null left over from a number | null type that's now number | undefined) are the same smell.
Reviewer action: comment "simplify the guard (see REVIEW.md §4)".