Allow Claude to code review PRs from forks

.github/workflows/claude.yml

@@ -27,10 +27,44 @@ jobs:
       id-token: write
       actions: read
     steps:
+      - name: Get PR details
+        if: |
+          (github.event_name == 'issue_comment' && github.event.issue.pull_request) ||
+          github.event_name == 'pull_request_review_comment' ||
+          github.event_name == 'pull_request_review'
+        id: pr
+        uses: actions/github-script@v7
+        with:
+          script: |
+            let prNumber;
+            if (context.eventName === 'issue_comment') {
+              prNumber = context.issue.number;
+            } else {
+              prNumber = context.payload.pull_request.number;
+            }
+
+            const pr = await github.rest.pulls.get({
+              owner: context.repo.owner,
+              repo: context.repo.repo,
+              pull_number: prNumber
+            });
+
+            core.setOutput('sha', pr.data.head.sha);
+            core.setOutput('repo', pr.data.head.repo.full_name);
+
+      - name: Checkout PR branch
+        if: steps.pr.outcome == 'success'
+        uses: actions/checkout@v4
+        with:
+          ref: ${{ steps.pr.outputs.sha }}
+          repository: ${{ steps.pr.outputs.repo }}
+          fetch-depth: 0
+
       - name: Checkout repository
+        if: steps.pr.outcome != 'success'
         uses: actions/checkout@v4
         with:
-          fetch-depth: 1
+          fetch-depth: 0
 
       - name: Run Claude Code
         id: claude