Issue deduplication: Claude finds and flags duplicate issues

Runs in GitHub Actions on your Claude Pro or Max plan through an OAuth token from claude setup-token. No API credits.

Set up the "Issue deduplication: Claude finds and flags duplicate issues" GitHub workflow from AgentFlows (https://agentflows.sh/flows/claude-code-action-issue-deduplication) so it runs on my Claude Pro or Max subscription instead of API credits.

Save this file as .github/workflows/claude-code-action-issue-deduplication.yml:

```yaml
name: Issue Deduplication

on:
  issues:
    types: [opened]

jobs:
  deduplicate:
    runs-on: ubuntu-latest
    timeout-minutes: 10
    permissions:
      contents: read
      issues: write
      id-token: write

    steps:
      - name: Checkout repository
        uses: actions/checkout@v6
        with:
          fetch-depth: 1

      - name: Check for duplicate issues
        uses: anthropics/claude-code-action@v1
        with:
          prompt: |
            Analyze this new issue and check if it's a duplicate of existing issues in the repository.

            Issue: #${{ github.event.issue.number }}
            Repository: ${{ github.repository }}

            Your task:
            1. Use mcp__github__get_issue to get details of the current issue (#${{ github.event.issue.number }})
            2. Search for similar existing issues using mcp__github__search_issues with relevant keywords from the issue title and body
            3. Compare the new issue with existing ones to identify potential duplicates

            Criteria for duplicates:
            - Same bug or error being reported
            - Same feature request (even if worded differently)
            - Same question being asked
            - Issues describing the same root problem

            If you find duplicates:
            - Add a comment on the new issue linking to the original issue(s)
            - Apply a "duplicate" label to the new issue
            - Be polite and explain why it's a duplicate
            - Suggest the user follow the original issue for updates

            If it's NOT a duplicate:
            - Don't add any comments
            - You may apply appropriate topic labels based on the issue content

            Use these tools:
            - mcp__github__get_issue: Get issue details
            - mcp__github__search_issues: Search for similar issues
            - mcp__github__list_issues: List recent issues if needed
            - mcp__github__create_issue_comment: Add a comment if duplicate found
            - mcp__github__update_issue: Add labels

            Be thorough but efficient. Focus on finding true duplicates, not just similar issues.

          claude_code_oauth_token: ${{ secrets.CLAUDE_CODE_OAUTH_TOKEN }}
          claude_args: |
            --allowedTools "mcp__github__get_issue,mcp__github__search_issues,mcp__github__list_issues,mcp__github__create_issue_comment,mcp__github__update_issue,mcp__github__get_issue_comments"
```

It authenticates with CLAUDE_CODE_OAUTH_TOKEN. Tell me to run `claude setup-token` in my own terminal to create it, then run `gh secret set CLAUDE_CODE_OAUTH_TOKEN` and let me paste it. Never write the token into a file.

It runs on: issues: opened. Runs count against my subscription's usage limits, and GitHub Actions minutes still apply.

Show me the diff, then commit on a new branch and open a pull request.