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>

crm-ops/skills/invoice/SKILL.md

@@ -1,17 +1,7 @@
 ---
 name: invoice
-description: >
-  Gestão de facturação Desk CRM v1.0. Criar, enviar, pagamentos, vencidas, timesheets.
-  Use when "invoice", "factura", "fatura", "pagamento", "vencida", "facturar", "billing".
-author: Descomplicar® Crescimento Digital
-version: 1.0.0
-quality_score: 75
-user_invocable: true
-category: business
-tags: [invoice, factura, billing, payments, desk, crm]
-desk_project: 65
-allowed-tools: Read, mcp__desk-crm-v3, mcp__mcp-time
-mcps: desk-crm-v3, mcp-time
+description: Gestão de facturação Desk CRM. Criar facturas, converter estimates, facturar timesheets, registar pagamentos e listar facturas vencidas.
+disable-model-invocation: true
 ---
 
 # /invoice v1.0 - Gestão de Facturação