observability

This skill should be used when the user asks about "observability" or "monitoring", what "metrics, logs, and traces" to collect, "health checks" (liveness/readiness), "alerting" or "on-call", "SLO/SLI" or "error budgets", the "RED" or "USE" method, "dashboards", or names a tool like "Prometheus", "Grafana", or "Datadog". Use it whenever a design has no answer to "how would we know this is broken?" or "what do we alert on?" — i.e. any time failure would be invisible until users complain, even if the user doesn't say "observability".