Align AGENTS.md with canonical Core Principles and PR Workflow

[glenn-jocher]

• AGENTS.md still carried an older four-principle Core Principles block and a four-step PR Workflow that named the Codex CLI specifically. Replaced both with the canonical Ultralytics text shared across the org; the repo-specific Commands, Architecture, and Conventions sections are unchanged.
• README's output-layout tree implied every conversion writes data.yaml. Only convert_labelme_json() does; convert_coco_json() writes one <json-stem>.yaml of class names per input file (write_coco_yaml). Noted inline.

🛠️ PR Summary

_{Made with ❤️ by Ultralytics Actions}

🌟 Summary

Clarifies repository contribution guidance and documents LabelMe versus COCO output YAML behavior. 📝

📊 Key Changes

• Reworked AGENTS.md to emphasize simple, owner-focused fixes, reuse of existing code, minimal scope, and zero-regression validation.
• Simplified the review workflow by removing mandatory adversarial-agent and PR-body requirements while retaining full-diff review and clean-head checks.
• Updated README.md to explain that:
  • LabelMe conversion creates a shared data.yaml.
  • COCO conversion creates one <json-stem>.yaml class-name file per input JSON.

🎯 Purpose & Impact

• Gives contributors and coding agents clearer, more streamlined development and review expectations. ✅
• Encourages smaller, cleaner changes by prioritizing deletion, reuse, and modifications to existing owners.
• Prevents confusion about generated dataset files, helping users locate the correct YAML configuration after conversion.
• The changes are documentation-only and should not affect converter functionality or runtime behavior. 🚀

[UltralyticsAssistant]

👋 Hello @glenn-jocher, thank you for submitting a ultralytics/JSON2YOLO 🚀 PR! This is an automated welcome message, and an engineer will assist with the review. To ensure a seamless integration of your work, please review the following checklist:

• ✅ Define a Purpose: Clearly explain the purpose of your fix or feature in your PR description, and link to any relevant issues. Ensure your commit messages are clear, concise, and adhere to the project's conventions.
• ✅ Synchronize with Source: Confirm your PR is synchronized with the ultralytics/JSON2YOLO main branch. If it's behind, update it by clicking the 'Update branch' button or by running git pull and git merge main locally.
• ✅ Ensure CI Checks Pass: Verify all Ultralytics Continuous Integration (CI) checks are passing. If any checks fail, please address the issues.
• ✅ Update Documentation: Update the relevant documentation for any new or modified features.
• ✅ Add Tests: If applicable, include or update tests to cover your changes, and confirm that all tests are passing.
• ✅ Sign the CLA: Please ensure you have signed our Contributor License Agreement if this is your first Ultralytics PR by writing "I have read the CLA Document and I sign the CLA" in a new message.
• ✅ Minimize Changes: Limit your changes to the minimum necessary for your bug fix or feature addition. "It is not daily increase but daily decrease, hack away the unessential. The closer to the source, the less wastage there is." — Bruce Lee

For more guidance, please refer to our Contributing Guide. Don't hesitate to leave a comment if you have any questions. Thank you for contributing to Ultralytics! 🚀

[UltralyticsAssistant]

🔍 PR Review

_{Made with ❤️ by Ultralytics Actions}

Clean PR. The AGENTS.md updates match the provided canonical principles and workflow, and the README clarification accurately reflects the converter behavior: LabelMe writes data.yaml, while COCO writes a YAML named after each input JSON file.

[UltralyticsAssistant]

🎉 Thank you, @glenn-jocher, and congratulations on the merge!

“The secret of getting ahead is getting started.” — Mark Twain

This PR makes it easier for contributors to get started with clear, focused guidance while documenting the different YAML outputs for LabelMe and COCO conversions. These thoughtful documentation improvements reduce confusion, support cleaner contributions, and help everyone work more effectively. We truly appreciate your contribution!