ci: add claude reusable workflow

.github/workflows/claude.yaml

@@ -0,0 +1,32 @@
+name: Claude Code
+
+on:
+  workflow_call:
+    secrets:
+      anthropic-api-key:
+        description: 'Anthropic API key for Claude Code agent'
+        required: true
+
+jobs:
+  claude:
+    if: |
+      (github.event_name == 'issue_comment' && contains(github.event.comment.body, '@claude')) ||
+      (github.event_name == 'pull_request_review_comment' && contains(github.event.comment.body, '@claude')) ||
+      (github.event_name == 'pull_request_review' && contains(github.event.review.body, '@claude'))
+    runs-on: ubuntu-latest
+    permissions:
+      contents: write
+      pull-requests: write
+      actions: read
+    steps:
+      - name: Checkout repository
+        uses: actions/checkout@de0fac2e4500dabe0009e67214ff5f5447ce83dd # v6.0.2
+        with:
+          fetch-depth: 1
+          persist-credentials: false
+
+      - name: Run Claude Code
+        id: claude
+        uses: anthropics/claude-code-action@88c168b39e7e64da0286d812b6e9fbebb6708185 # v1
+        with:
+          anthropic_api_key: ${{ secrets.anthropic-api-key }} # zizmor: ignore[secrets-outside-env] -- API key passed via workflow_call, not a repo secret