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/agent-context-injector/SKILL.md

@@ -1,12 +1,7 @@
 ---
 name: agent-context-injector
-description: >
-  Injecção dinâmica de contexto específico para cada agente.
-  Use when "contexto agente", "injectar", "SubagentStart",
-  "recursos agente", "mcps disponíveis", "skills relevantes".
-author: Descomplicar®
-version: 1.0.0
-desk_task: 1441
+description: Injecção dinâmica de contexto específico para cada agente — MCPs disponíveis, skills relevantes e datasets Dify.
+user-invocable: false
 allowed-tools: Read, Glob, Grep, ToolSearch
 ---