PR Anti-pattern Review

Review a diff by comparing it against the project's slice catalog. Find deviations from declared slices and universal anti-patterns. Output a review with path:line references suitable for pasting as PR comments.

This skill is comparative, not encyclopedic. It compares the diff against BLUEPRINT.md rather than running a generic checklist.

Output is ephemeral by default. Findings go to chat. Save to a file only if the user asks.

Core principles

1. Blueprint is the rulebook. If the project has a BLUEPRINT.md, that determines what's right vs wrong. Findings without a blueprint anchor are weaker (suggestions, not violations).
2. Slices are the unit of comparison. The question isn't "does this PR violate generic principles" but "does this PR follow the slice it's working in".
3. Human-in-the-loop on judgment calls. Don't decide severity in ambiguous cases. Don't classify deviations as deliberate vs accidental — ask.
4. Boy scout rule. Pre-existing problems in touched files are not held against the PR unless it makes them worse.
5. Output is ephemeral. Findings emitted to chat. Never auto-write a file. Never auto-commit.