Add comprehensive Agent Skill for systematic code refactoring with:
- Main SKILL.md with 6-phase workflow (research, test coverage, smell
identification, planning, implementation, review)
- Code smells reference catalog (22+ smells with examples)
- Refactoring techniques catalog (25+ techniques with mechanics)
- Refactoring plan template for tracking progress
- Python scripts for complexity analysis and smell detection
- User consultation points at each decision phase
- Safety guidelines emphasizing tests and small steps
Luong NGUYEN