Clean up Code Review Skill

[mrsharm]

No description provided.

[Copilot]

Pull request overview

This PR restructures the code-review skill documentation by moving the large rule lists out of SKILL.md into focused reference markdown files, and updates the skill text to direct reviewers to load the relevant references on demand.

Changes:

• Expanded the code-review skill’s frontmatter description to better describe when to use it and what it covers.
• Updated Step 4 to explicitly instruct loading the appropriate rule reference(s) before flagging issues.
• Extracted the detailed rule sections into separate references/*.md files and added a “Rule Reference Index” table linking to them.

Reviewed changes

Copilot reviewed 9 out of 9 changed files in this pull request and generated 1 comment.

Show a summary per file

File	Description
.github/skills/code-review/SKILL.md	Updates the skill description, adds “load references first” guidance, and replaces embedded rule blocks with a “Rule Reference Index” pointing to new reference docs.
.github/skills/code-review/references/testing.md	New: testing/regression-test conventions extracted into a dedicated reference.
.github/skills/code-review/references/platform-and-native.md	New: cross-platform, native/interop, and VM/runtime patterns reference.
.github/skills/code-review/references/performance.md	New: performance and allocation guidance reference.
.github/skills/code-review/references/documentation.md	New: documentation/commenting and breaking-change guidance reference.
.github/skills/code-review/references/correctness-and-safety.md	New: correctness, safety, thread-safety, and security guidance reference.
.github/skills/code-review/references/codebase-consistency.md	New: PR hygiene, deduplication, and codebase consistency guidance reference.
.github/skills/code-review/references/code-style.md	New: code style/formatting guidance reference.
.github/skills/code-review/references/api-design.md	New: API design/approval/contract guidance reference.