This PR updates the README.md with a complete TODO list extracted from all Python files in the repository.

Changes:

• Added ### 📝 Complete TODO List section to README.md
• Extracted 108 TODO items from all Python files
• Grouped TODOs by directory for better organization
• Items are sorted by file path (lexicographically) and line number

The TODO list was generated by scanning all .py files in the luffy/ directory and extracting TODO comments. Items from the ExGRPO/ directory that were duplicates were removed.

TODO statistics:

• Total TODO items: 108
• Directories covered: 12
• Files with TODOs: 42

This helps track all pending work items in the codebase and makes it easier for contributors to find tasks to work on.