feat: mark clean-code & clean-architecture as MANDATORY

- 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

hooks/scripts/detect-project.sh

@@ -68,7 +68,7 @@ CORE="engineering-principles, clean-code, clean-architecture, testing, error-han
 SKILLS="${SKILLS#, }"  # strip leading ", "
 
 echo "📐 [hub-guide] detected: ${PROJECT_DIR}"
-echo "📐 [hub-guide] core skills: ${CORE}"
+echo "📐 [hub-guide] mandatory: ${CORE}"
 if [ -n "$SKILLS" ]; then
   echo "📐 [hub-guide] project-specific: ${SKILLS}"
 fi

skills/clean-architecture/SKILL.md

@@ -1,6 +1,6 @@
 ---
 name: clean-architecture
-description: Apply Clean Architecture, hexagonal architecture, and SOLID principles when designing system boundaries, modules, or microservices. Use when structuring a new service, deciding what a component should own, untangling framework coupling. Detects from code context and project files — not dependent on specific language keywords."
+description: MANDATORY — always active. Clean Architecture, hexagonal architecture, and SOLID principles. Apply to every session regardless of context. Use when structuring services, modules, microservices, or untangling framework coupling. Always enforce the Dependency Rule — business rules must not depend on frameworks, databases, or UI. Detects from code context regardless of spoken language.
 ---
 
 # Clean Architecture

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 the user mentions clean-code concepts in any language. Also engage proactively from code quality signals — poor naming, long functions, deep nesting, unclear abstractions — regardless of spoken language. Detects from code context and project files — not dependent on specific language keywords.
+description: MANDATORY — always active. Clean Code principles: naming, functions, comments, formatting, error handling, classes. Apply to every session regardless of context. Use whenever the user writes code, reviews code, refactors, or mentions clean-code concepts in any language. Also engage proactively from code quality signals — poor naming, long functions, deep nesting, unclear abstractions. Works regardless of spoken language.
 ---
 
 # Clean Code