[2.15.2] Fix skill spec compliance across all skills

Fixed issues flagged by skill-creator spec:
- Reference files now use proper markdown links instead of backtick text
- Descriptions use third person ("This skill should be used when...")
- Added Skill Compliance Checklist to CLAUDE.md with validation commands

Affected skills: agent-native-architecture, andrew-kane-gem-writer,
compound-docs, create-agent-skills, dhh-rails-style, dhh-ruby-style,
dspy-ruby, every-style-editor, file-todos, frontend-design, gemini-imagegen

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

plugins/compound-engineering/skills/frontend-design/SKILL.md

@@ -1,6 +1,6 @@
 ---
 name: frontend-design
-description: Create distinctive, production-grade frontend interfaces with high design quality. Use this skill when the user asks to build web components, pages, or applications. Generates creative, polished code that avoids generic AI aesthetics.
+description: This skill should be used when creating distinctive, production-grade frontend interfaces with high design quality. It applies when the user asks to build web components, pages, or applications. Generates creative, polished code that avoids generic AI aesthetics.
 license: Complete terms in LICENSE.txt
 ---