Add claude-react-on-comment workflow

Add the Claude bot workflow that reacts to @phpstan-bot mentions.
Triggers on issue comments, PR reviews, PR review comments, and
newly opened issues. The COMMENT_BODY includes a fallback chain
to support all trigger contexts (comment body, review body, and
issue body).

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

Author: 2 people

.github/workflows/claude-react-on-comment.yml

@@ -0,0 +1,65 @@
+name: "Claude React on comment"
+
+on:
+  issues:
+    types: [opened]
+  issue_comment:
+    types: [created]
+  pull_request_review:
+    types: [submitted]
+  pull_request_review_comment:
+    types: [created]
+
+permissions:
+  contents: write
+  pull-requests: write
+  issues: write
+  actions: read
+
+concurrency:
+  group: claude-pr-reactions-${{ github.event.pull_request.number || github.event.issue.number }}
+  cancel-in-progress: false
+
+jobs:
+  check-trigger:
+    name: "Check trigger phrase"
+    runs-on: ubuntu-latest
+    timeout-minutes: 1
+    outputs:
+      triggered: ${{ steps.check.outputs.triggered }}
+    steps:
+      - name: "Check for trigger phrase"
+        id: check
+        env:
+          COMMENT_BODY: ${{ github.event.comment.body || github.event.review.body || github.event.issue.body || '' }}
+        run: |
+          if echo "$COMMENT_BODY" | grep -qF "@phpstan-bot"; then
+            echo "triggered=true" >> "$GITHUB_OUTPUT"
+          else
+            echo "triggered=false" >> "$GITHUB_OUTPUT"
+          fi
+
+  react:
+    name: "React on comment"
+    needs: check-trigger
+    if: needs.check-trigger.outputs.triggered == 'true'
+    runs-on: ubuntu-latest
+    timeout-minutes: 60
+
+    steps:
+      - name: "Checkout"
+        uses: actions/checkout@v4
+        with:
+          token: ${{ secrets.PHPSTAN_BOT_TOKEN }}
+
+      - name: "React to feedback"
+        uses: anthropics/claude-code-action@v1
+        with:
+          claude_code_oauth_token: ${{ secrets.CLAUDE_CODE_OAUTH_TOKEN }}
+          github_token: ${{ secrets.PHPSTAN_BOT_TOKEN }}
+          trigger_phrase: "@phpstan-bot"
+          claude_args: "--model claude-opus-4-6"
+          bot_name: "phpstan-bot"
+          bot_id: "79867460"
+          additional_permissions: |
+            actions: read