feat: add structured decision format and auto-close for rejected PRs

Enhance the Claude PR review workflow with:
- Remove redundant criteria mention (already in CONTRIBUTING.md)
- Add file access restrictions to prevent unnecessary file reads
- Require structured DECISION output format for automation
- Auto-close rejected PRs with explanatory comment

🤖 Generated with Claude Code (https://claude.ai/code)
Co-Authored-By: Claude <noreply@anthropic.com>

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

@@ -39,6 +39,20 @@ jobs:
           plugins: "code-review@claude-code-plugins"
           prompt: |
             Review this PR against the acceptance criteria in CONTRIBUTING.md.
-            Focus on: Industry Standard, Rising Star, or Hidden Gem criteria.
             Check for automatic rejection reasons (abandoned, duplicates, spam).
+
+            IMPORTANT: Only read README.md and CONTRIBUTING.md. Do not read or access any other files.
+
             /code-review:code-review ${{ github.repository }}/pull/${{ github.event.pull_request.number }}
+
+            After your review, output your final decision on the LAST line in this exact format:
+            DECISION: REJECT or DECISION: PASS
+
+      - name: Close PR if rejected
+        if: contains(steps.claude-review.outputs.response, 'DECISION: REJECT')
+        env:
+          GH_TOKEN: ${{ github.token }}
+        run: |
+          gh pr close ${{ github.event.pull_request.number }} \
+            --repo ${{ github.repository }} \
+            --comment "This PR has been automatically closed based on the review. Please address the feedback and re-open the PR."