ci: respond to PR comments via claude-code-action on the Max plan

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

@@ -0,0 +1,67 @@
+---
+name: Claude PR comment handler
+
+# Respond to every human comment/review on a PR — no @claude mention needed.
+# Runs on the Max subscription via CLAUDE_CODE_OAUTH_TOKEN (not API credits).
+"on":
+  issue_comment:
+    types: [created]
+  pull_request_review_comment:
+    types: [created]
+  pull_request_review:
+    types: [submitted]
+
+# One run per PR; newer comments supersede an in-flight run.
+concurrency:
+  group:
+    claude-pr-comment-${{ github.event.issue.number ||
+    github.event.pull_request.number }}
+  cancel-in-progress: false
+
+permissions:
+  contents: write
+  pull-requests: write
+  issues: write
+  id-token: write
+
+jobs:
+  respond:
+    # Only on PR-attached comments, with a non-empty body, and never from a bot
+    # (the loop guard: Claude's own replies are bot comments, so they can't
+    # re-trigger this workflow).
+    if: >
+      github.event.sender.type != 'Bot' && (
+        (github.event_name == 'issue_comment' && github.event.issue.pull_request
+      != null)
+        || github.event_name == 'pull_request_review_comment'
+        || (github.event_name == 'pull_request_review' &&
+      github.event.review.body != '')
+      )
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v6
+        with:
+          fetch-depth: 0
+
+      - uses: anthropics/claude-code-action@v1
+        with:
+          claude_code_oauth_token: ${{ secrets.CLAUDE_CODE_OAUTH_TOKEN }}
+          # Belt-and-suspenders loop guard alongside the sender.type check above.
+          exclude_comments_by_actor: "etrobert-bot,github-actions[bot],claude[bot]"
+          prompt: |
+            A human just left a comment or review on this pull request. Read it
+            in the full context of the PR diff and the conversation so far, then
+            handle it:
+
+            - If it requests a change, or makes a suggestion you agree with,
+              implement it and push a commit to this PR's branch.
+            - If it asks a question, answer it as a reply.
+            - If it is purely informational (e.g. "thanks", "lgtm"), a brief
+              acknowledgement is enough — don't manufacture work.
+
+            Follow this repo's Conventional Comments convention (issue,
+            question, suggestion, nitpick). Always reply on the thread so the
+            author knows the comment was handled. Do NOT merge — a human reviews
+            and merges.
+          claude_args: |
+            --max-turns 20