feat(.ai): code review skill

[marissahuysentruyt]

Description

⚠️ NICE-TO-HAVE PARALLEL MERGE ⚠️
Can be merged directly into feat-agnostic-ai-folder-stuff before or after the washing machine skills PR #6127 or the skills mindset PR #6139

Adds a .ai skill (pr-review) for performing automated first-round code reviews before opening a PR to the team. The skill compares the current branch against a base branch, inspects the diff, runs targeted checks against repo guidance, and writes a structured review report to .ai/pr-feedback/ (which is git-ignored).

Changes:

• .ai/skills/pr-review/SKILL.md: skill definition and workflow
• .ai/skills/pr-review/references/pr-review-prompt.md: reference prompt driving the review logic
• .ai/skills/pr-review/references/pr-feedback-template.md: output template for generated review reports
• .ai/skills/pr-review/scripts/create_pr_feedback.py: Python script that scaffolds the feedback file
• .ai/README.md: updated to document the new skill
• .gitignore: excludes .ai/pr-feedback

Motivation and context

Code review feedback is only useful if it's consistent and tied to the project's own conventions. This skill gives contributors a first-pass review grounded in 2nd-gen component guidance — CSS style, TypeScript patterns, accessibility, and testing — before the PR reaches the team. It reduces review cycle time and surfaces fixable issues early.

Related issue(s)

• fixes swc-1895

Screenshots (if appropriate)

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Author's checklist

• I have read the CONTRIBUTING and PULL_REQUESTS documents.
• I have reviewed at the Accessibility Practices for this feature, see: Aria Practices
• I have added automated tests to cover my changes.
• I have included a well-written changeset if my change needs to be published.
• I have included updated documentation if my change required it.

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Reviewer's checklist

• Includes a Github Issue with appropriate flag or Jira ticket number without a link
• Includes thoughtfully written changeset if changes suggested include patch, minor, or major features
• Automated tests cover all use cases and follow best practices for writing
• Validated on all supported browsers
• All VRTs are approved before the author can update Golden Hash

Manual review test cases

• PR review skill generates a valid feedback report

1. On a branch with 2nd-gen component changes, invoke the pr-review skill
2. Expect create_pr_feedback.py to scaffold a numbered file in .ai/pr-feedback/
3. Expect the report to include findings organized by the template structure (CSS, TypeScript, accessibility, testing)

• Skill correctly uses a custom base branch when specified

1. Invoke the skill with a non-main base branch (e.g. marissahuysentruyt/feat-agnostic-folder-ai-stuff)
2. Expect the diff and review to reflect only the commits on the current branch vs that base

Device review

• Did it pass in Desktop?
• Did it pass in (emulated) Mobile?
• Did it pass in (emulated) iPad?

Accessibility testing checklist

Required: Complete each applicable item and document your testing steps (replace the placeholders with your component-specific instructions).

• Keyboard
  documentation update only

• Screen reader
  documentation update only

[changeset-bot]

⚠️ No Changeset found

Latest commit: 7771aab

Merging this PR will not cause a version bump for any packages. If these changes should not result in a new version, you're good to go. If these changes should result in a version bump, you need to add a changeset.

This PR includes no changesets

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[github-actions]

📚 Branch Preview Links

• Documentation Site (first-gen)
• Storybook (first-gen)
• Storybook (second-gen)

🔍 First Generation Visual Regression Test Results

When a visual regression test fails (or has previously failed while working on this branch), its results can be found in the following URLs:

• Spectrum | Light | Medium | LTR
• Spectrum | Dark | Large | RTL
• Express | Light | Medium | LTR
• Express | Dark | Large | RTL
• Spectrum-two | Light | Medium | LTR
• Spectrum-two | Dark | Large | RTL
• High Contrast Mode | Medium | LTR

Deployed to Azure Blob Storage: pr-6148

If the changes are expected, update the current_golden_images_cache hash in the circleci config to accept the new images. Instructions are included in that file.
If the changes are unexpected, you can investigate the cause of the differences and update the code accordingly.