Refine plugin marketplace for launch readiness

Plugin Scope Improvements:
- Remove language-specialists plugin (not task-focused)
- Split specialized-domains into 5 focused plugins:
  * blockchain-web3 - Smart contract development only
  * quantitative-trading - Financial modeling and trading only
  * payment-processing - Payment gateway integration only
  * game-development - Unity and Minecraft only
  * accessibility-compliance - WCAG auditing only
- Split business-operations into 3 focused plugins:
  * business-analytics - Metrics and reporting only
  * hr-legal-compliance - HR and legal docs only
  * customer-sales-automation - Support and sales workflows only
- Fix infrastructure-devops scope:
  * Remove database concerns (db-migrate, database-admin)
  * Remove observability concerns (observability-engineer)
  * Move slo-implement to incident-response
  * Focus purely on container orchestration (K8s, Docker, Terraform)
- Fix customer-sales-automation scope:
  * Remove content-marketer (unrelated to customer/sales workflows)

Marketplace Statistics:
- Total plugins: 27 (was 22)
- Tool coverage: 100% (42/42 tools referenced)
- Fat plugins removed: 3 (language-specialists, specialized-domains, business-operations)
- All plugins now have clear, focused tasks

Model Migration:
- Migrate all 42 tools from claude-sonnet-4-0/opus-4-1 to model: sonnet
- Migrate all 15 workflows from claude-opus-4-1 to model: sonnet
- Use short model syntax consistent with agent files

Documentation Updates:
- Update README.md with refined plugin structure
- Update plugin descriptions to be task-focused
- Remove anthropomorphic and marketing language
- Improve category organization (now 16 distinct categories)

Ready for October 9, 2025 @ 9am PST launch

tools/db-migrate.md

@@ -1,5 +1,5 @@
 ---
-model: claude-sonnet-4-0
+model: sonnet
 ---
 
 # Database Migration Strategy and Implementation