Add simple PR review slash command for GitHub Actions

- Reviews PR using embedded GitHub Actions variables
- Fetches PR details and diff using gh CLI
- Posts review as comment using gh pr comment
- Designed for use in automated workflows

.claude/commands/review.md

@@ -0,0 +1,44 @@
+---
+allowed-tools: Bash(gh pr view:*), Bash(gh pr diff:*), Bash(gh pr comment:*), Bash(gh api:*), Read, Glob, Grep
+description: Review the current PR in GitHub Actions
+---
+
+Review PR #${{ github.event.pull_request.number }} and post a comment with your findings.
+
+## Steps
+
+1. Get the PR details to understand context:
+   ```bash
+   gh pr view ${{ github.event.pull_request.number }} --repo ${{ github.repository }} --json title,body,author,state,isDraft,files,baseRefName,headRefName
+   ```
+
+2. Get the diff to see what changed:
+   ```bash
+   gh pr diff ${{ github.event.pull_request.number }} --repo ${{ github.repository }}
+   ```
+
+3. Review the changes focusing on:
+   - Code quality and best practices
+   - Potential bugs or security issues
+   - Performance concerns
+   - Missing tests or documentation
+   - Consistency with existing codebase
+
+4. Write your review to a file, then post it:
+   ```bash
+   cat > /tmp/pr-review.md << 'EOF'
+   ## Code Review
+   
+   [Your review here - be specific and constructive]
+   
+   🤖 Generated with [Claude Code](https://claude.ai/code)
+   EOF
+   
+   gh pr comment ${{ github.event.pull_request.number }} --repo ${{ github.repository }} --body-file /tmp/pr-review.md
+   ```
+
+## Important
+- Be constructive and specific
+- Reference specific files and line numbers when pointing out issues
+- Acknowledge what's done well
+- Provide actionable suggestions for improvements