- Add MANDATORY prefix to clean-code and clean-architecture descriptions
- Change 'core skills' to 'mandatory' in detect-project.sh output
- Both skills now always active, not just context-triggered
- Add principle 27: 'Language-Agnostic Auto-Trigger' to engineering-principles
- Remove hardcoded English-only keyword lists from all 26 skill descriptions
- Replace with concept-based detection: triggers from code context, project files,
and file types regardless of spoken language
- Update detect-project.sh hook output with language-agnostic message