Update workflow to use /review slash command

.github/workflows/claude-auto-review.yml

@@ -23,21 +23,4 @@ jobs:
         uses: anthropics/claude-code-action@v1-dev
         with:
           anthropic_api_key: ${{ secrets.ANTHROPIC_API_KEY }}
-          prompt: |
-            Please review this pull request and provide comprehensive feedback.
-            
-            Focus on:
-            - Code quality and best practices
-            - Potential bugs or issues  
-            - Suggestions for improvements
-            - Overall architecture and design decisions
-            - Documentation consistency
-            
-            Steps:
-            1. Use mcp__github__get_pull_request to get PR details
-            2. Use mcp__github__get_pull_request_diff to see the changes
-            3. Use mcp__github__create_pending_pull_request_review to start a review
-            4. Use mcp__github__add_comment_to_pending_review for specific feedback
-            5. Use mcp__github__submit_pending_pull_request_review with event: COMMENT to submit
-            
-            Create a review with constructive feedback and submit it as a COMMENT (not APPROVE).
+          prompt: /review