Prometheus

• Alerting

  The controller's Kubernetes Events on StageSet transitions, the opt-in PrometheusRule alert catalog with tunable thresholds, and how every alert and Ready reason links to a runbook.

• Metrics

  The controller's Prometheus metrics — the stageset_* custom series and controller-runtime signals, scraping with a ServiceMonitor or a plain config, querying with PromQL, and the chart values that drive them.