Add optional fetch_depth parameter for shallow clones

[justinxu421]

Add configurable git checkout depth for performance optimization

Introduces an optional fetch_depth parameter that allows users to control the number of commits fetched during checkout, enabling shallow clones for faster performance on large repositories.

Key Changes

• Add fetch_depth input parameter to the action with a default value of 0 (full history)
• Update checkout step to use the configurable depth instead of hardcoded value
• Document the new parameter in the README inputs table
• Add "Performance Optimization" section with usage examples

Benefits

• Faster checkouts: Shallow clones can significantly reduce checkout time for repositories with extensive history
• Flexible configuration: Users can choose the optimal depth based on their needs
• Backward compatible: Default behavior remains unchanged (full history)

Usage Example

- name: Generate PR Description
  uses: augmentcode/describe-pr@v0
  with:
    augment_session_auth: ${{ secrets.AUGMENT_SESSION_AUTH }}
    github_token: ${{ secrets.GITHUB_TOKEN }}
    pull_number: ${{ github.event.pull_request.number }}
    repo_name: ${{ github.repository }}
    fetch_depth: 50  # Only fetch last 50 commits for faster checkout

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[github-actions]

Review completed. The implementation looks solid overall - the feature is well-designed and properly documented. I have one minor suggestion about type handling for the fetch_depth parameter.

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🤖 Automated review complete. Please react with 👍 or 👎 on the individual review comments to provide feedback on their usefulness.

[justinxu421]

augment review

[augment-app-staging]

Clear, backward-compatible addition of a configurable checkout depth with matching documentation updates. The default preserves existing behavior while enabling performance tuning. Review completed with no suggestions at this time.