fix: update Claude Code Review workflow for improved functionality

- Adjusted checkout step to use pull request merge reference and disabled credential persistence.
- Cleaned up whitespace for better readability.
- Enhanced guidance on using the repository's CLAUDE.md for style and conventions.

These changes aim to streamline the code review process and ensure proper integration with GitHub actions.

Author: Gkrumbach07

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

@@ -17,18 +17,20 @@ jobs:
     #   github.event.pull_request.user.login == 'external-contributor' ||
     #   github.event.pull_request.user.login == 'new-developer' ||
     #   github.event.pull_request.author_association == 'FIRST_TIME_CONTRIBUTOR'
-    
+
     runs-on: ubuntu-latest
     permissions:
       contents: read
       pull-requests: read
       issues: read
       id-token: write
-    
+
     steps:
       - name: Checkout repository
         uses: actions/checkout@v4
         with:
+          ref: refs/pull/${{ github.event.number }}/merge
+          persist-credentials: false
           fetch-depth: 1
 
       - name: Run Claude Code Review
@@ -43,12 +45,11 @@ jobs:
             - Performance considerations
             - Security concerns
             - Test coverage
-            
+
             Use the repository's CLAUDE.md for guidance on style and conventions. Be constructive and helpful in your feedback.
 
             Use `gh pr comment` with your Bash tool to leave your review as a comment on the PR.
-          
+
           # See https://github.com/anthropics/claude-code-action/blob/main/docs/usage.md
           # or https://docs.anthropic.com/en/docs/claude-code/sdk#command-line for available options
           claude_args: '--allowed-tools "Bash(gh issue view:*),Bash(gh search:*),Bash(gh issue list:*),Bash(gh pr comment:*),Bash(gh pr diff:*),Bash(gh pr view:*),Bash(gh pr list:*)"'
-