Add Claude Code security review workflow

Run AI-powered security analysis on PRs after approval.
Fails the check if vulnerabilities are found, with admin bypass
via branch protection rules.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

Author: mfo

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

@@ -0,0 +1,30 @@
+name: Claude Code Security Review
+
+on:
+  pull_request_review:
+    types: [submitted]
+
+permissions:
+  contents: read
+  pull-requests: write
+
+jobs:
+  security-review:
+    if: github.event.review.state == 'approved'
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v4
+        with:
+          ref: ${{ github.event.pull_request.head.sha }}
+          fetch-depth: 2
+
+      - uses: anthropics/claude-code-security-review@main
+        id: scan
+        with:
+          claude-api-key: ${{ secrets.CLAUDE_API_KEY }}
+
+      - name: Fail if security findings
+        if: steps.scan.outputs.findings-count > 0
+        run: |
+          echo "::error::Security review found ${{ steps.scan.outputs.findings-count }} finding(s). Review the comments on this PR."
+          exit 1