feat(hub-guide): language-agnostic auto-trigger across all skills

- 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

skills/clean-code/SKILL.md

@@ -1,6 +1,6 @@
 ---
 name: clean-code
-description: Apply Robert C. Martin's (Uncle Bob's) Clean Code, Clean Architecture, and Clean Craftsmanship principles when writing, reviewing, or refactoring code. Use this skill whenever the user asks to write new code of non-trivial size, refactor existing code, review code for quality, design a module or system boundary, write tests, or whenever the user mentions "clean code," "clean architecture," "SOLID," "SRP," "OCP," "LSP," "ISP," "DIP," "TDD," "refactor," "code smells," or "Uncle Bob."Line truncated
+description: Apply Robert C. Martin's (Uncle Bob's) Clean Code, Clean Architecture, and Clean Craftsmanship principles when writing, reviewing, or refactoring code. Use this skill whenever the user asks to write new code of non-trivial size, refactor existing code, review code for quality, design a module or system boundary, write tests, or the user mentions clean-code concepts in any language. Also engage proactively from code quality signals — poor naming, long functions, deep nesting, unclLine truncated
 ---
 
 # Clean Code