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## Summary by cubic
Switches the duplicate-issues GitHub Action from
anthropic/claude-sonnet-4-20250514 to openai/gpt-5 to reduce cost.
Updates the workflow to use OPENAI_API_KEY instead of ANTHROPIC_API_KEY.
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<!-- This is an auto-generated description by cubic. -->
## Summary by cubic
Adds a GitHub Action to detect and comment on potential duplicate issues
when a new issue is opened. This reduces triage time and keeps issue
lists clean.
- **New Features**
- Adds .github/workflows/duplicate-issues.yml triggered on issues:
opened.
- Uses opencode with Anthropic Claude Sonnet 4 to scan existing issues
and comment with links if duplicates are likely; stays silent otherwise.
- Runs with minimal permissions; allows gh issue commands and denies
webfetch.
- **Migration**
- Create the ai-bots environment and add the ANTHROPIC_API_KEY secret
(GITHUB_TOKEN is provided by GitHub).
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