feat: add review mode workflow for testing

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

@@ -0,0 +1,45 @@
+name: Claude Review Mode
+
+on:
+  pull_request:
+    types: [opened, synchronize]
+  issue_comment:
+    types: [created]
+
+jobs:
+  code-review:
+    # Run on PR events, or when someone comments "@claude review" on a PR
+    if: |
+      github.event_name == 'pull_request' ||
+      (github.event_name == 'issue_comment' && 
+       github.event.issue.pull_request && 
+       contains(github.event.comment.body, '@claude review'))
+    runs-on: ubuntu-latest
+    permissions:
+      contents: read
+      pull-requests: write
+      issues: write
+      # Note: id-token not needed since review mode doesn't use OIDC for GitHub auth
+    steps:
+      - name: Checkout repository
+        uses: actions/checkout@v4
+        with:
+          fetch-depth: 0  # Full history for better diff analysis
+
+      - name: Code Review with Claude
+        uses: km-anthropic/claude-code-action@main
+        with:
+          mode: review
+          anthropic_api_key: ${{ secrets.ANTHROPIC_API_KEY }}
+          # github_token not needed - uses default GITHUB_TOKEN for GitHub operations
+          timeout_minutes: "30"
+          custom_instructions: |
+            Focus on:
+            - Code quality and maintainability
+            - Security vulnerabilities
+            - Performance issues
+            - Best practices and design patterns
+            - Test coverage gaps
+            
+            Be constructive and provide specific suggestions for improvements.
+            Use GitHub's suggestion format when proposing code changes.