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>

gestao/.claude-plugin/plugin.json

@@ -1,6 +1,6 @@
 {
   "name": "gestao",
-  "description": "Project management, time tracking, daily checkups, worklogs, reflections, knowledge management, archiving and compliance auditing. Backed by 6 Dify KB datasets.",
+  "description": "Project management, time tracking, daily checkups, worklogs, reflections, knowledge management, archiving and compliance auditing. Backed by NotebookLM notebooks.",
   "version": "1.3.0",
   "author": {
     "name": "Descomplicar - Crescimento Digital",