feat(hub-guide): language-agnostic auto-trigger across all skills

- Add principle 27: 'Language-Agnostic Auto-Trigger' to engineering-principles
- Remove hardcoded English-only keyword lists from all 26 skill descriptions
- Replace with concept-based detection: triggers from code context, project files,
  and file types regardless of spoken language
- Update detect-project.sh hook output with language-agnostic message

skills/monitoring/SKILL.md

@@ -1,6 +1,6 @@
 ---
 name: monitoring
-description: Monitoring and observability best practices — Prometheus, Grafana, alerts, dashboards, uptime monitoring, and incident response. Use when setting up monitoring infrastructure, designing dashboards, defining alerts, or whenever the user mentions "monitoring," "Prometheus," "Grafana," "alert," "dashboard," "uptime," "incident," "runbook," "SLA," "SLO," "SLI," or "on-call."
+description: Monitoring and observability best practices — Prometheus, Grafana, alerts, dashboards, uptime monitoring, and incident response. Use when setting up monitoring infrastructure, designing dashboards, defining alerts. Triggers from project files and configuration, not just keyword matching."
 ---
 
 # Monitoring Best Practices