Motivation

Our CI/CD infrastructure is complex and was lacking proper documentation, making it challenging for newcomers and contributors to understand the system. This PR adds comprehensive documentation to:

• Make our CI/CD architecture more accessible to new contributors
• Document workflow relationships and dependencies
• Explain infrastructure components and their roles
• Provide best practices and known limitations

Closes #9112

Specifications & References

• GitHub Actions Path Filtering Limitation
• GitHub Actions Variables in Forks Limitation
• Rust Caching Limitations

Solution

1. Added detailed CI/CD documentation in .github/workflows/README.md:

   • Table of contents for easy navigation
   • System overview and core infrastructure details
   • Mermaid diagram showing workflow relationships and parallel execution
   • Detailed sections on:
     • Core infrastructure components
     • Workflow organization
     • Test execution strategy
     • Infrastructure details
     • Best practices
     • Known issues

2. Added CI/CD section to main README.md:

   • Brief overview of CI/CD capabilities
   • Strategic placement between Getting Started and Documentation sections
   • Direct link to detailed documentation

3. Documentation improvements:

   • Clear explanation of patch workflows and their rationale
   • Detailed infrastructure dependencies and requirements
   • Comprehensive coverage of test execution patterns
   • External contributor considerations and limitations

PR Author's Checklist

• The PR name will make sense to users.
• The PR provides a CHANGELOG summary.
• The solution is tested.
• The documentation is up to date.
• The PR has a priority label.

PR Reviewer's Checklist

• The PR Author's checklist is complete.
• The PR resolves the issue.