feat: refactor 30+ skills to Anthropic progressive disclosure pattern

- All SKILL.md files now <500 lines (avg reduction 69%)
- Detailed content extracted to references/ subdirectories
- Frontmatter standardised: only name + description (Anthropic standard)
- New skills: brand-guidelines, spec-coauthor, report-templates, skill-creator
- Design skills: anti-slop guidelines, premium-proposals reference
- Removed non-standard frontmatter fields (triggers, version, author, category)

Plugins affected: infraestrutura, marketing, dev-tools, crm-ops, gestao,
core-tools, negocio, perfex-dev, wordpress, design-media

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

core-tools/skills/plugin-manager/SKILL.md

@@ -1,17 +1,7 @@
 ---
 name: plugin-config
-description: >
-  Gestao inteligente de plugins por contexto v3.0. Avalia regras aditivas — activa
-  cada plugin que fizer sentido para o contexto actual (directorio, ficheiros, conversa).
-  Sem profiles rigidos. Use when "plugins", "plugin-config", "activar plugin",
-  "desactivar plugin", "contexto plugins", "prompt too long".
-author: Descomplicar
-version: 3.1.0
-user_invocable: true
-category: system
-tags: [plugins, context, optimization, registry]
-desk_project: 65
-desk_task: 1754
+description: Gestão inteligente de plugins por contexto. Avalia regras aditivas e activa cada plugin relevante para o contexto actual (directório, ficheiros, conversa).
+user-invocable: false
 allowed-tools: Read, Bash, Glob
 ---