docs: add release checklist and simplify AGENT.md

[himanshu231204]

Summary

• Created Release.md — quick reference release checklist
• Updated AGENT.md to reference Release_Guide.md and Release.md
• Simplified AGENT.md from 234 lines to 116 lines

Changes

AGENT.md

• Removed detailed release workflow (moved to Release_Guide.md)
• Added reference to Release_Guide.md for full workflow
• Added reference to Release.md for quick checklist
• Kept only key rules (7 bullet points)

Release.md (New)

• Pre-release checklist
• Update version steps
• Create release branch & PR commands
• Tag release commands
• GitHub Release checklist
• Post-release verification
• Semantic versioning table
• Release notes format template
• Files involved table
• Troubleshooting section

Benefits

• ✅ AGENT.md is now concise (116 lines vs 234 lines)
• ✅ Release.md provides quick reference checklist
• ✅ Clear separation of concerns
• ✅ Easy to maintain and update

[github-actions]

🎉 Congratulations @himanshu231204!

Your pull request has been successfully merged into main. 🚀

Thank you for contributing to OpenAgentHQ and helping improve the project.

We truly appreciate your contribution and hope to see you back with more amazing PRs!

Happy Open Sourcing! ❤️