The kube-controller-manager is a core Kubernetes control plane component responsible for running controllers that continuously monitor the cluster’s state and ensure it matches the desired configuration. These controllers handle important tasks such as node management, replication control, endpoint updates, job execution, and namespace management. By automating these operations, the Controller Manager helps maintain cluster stability, reliability, and self-healing capabilities. In your opinion, why is the kube-controller-manager essential for Kubernetes cluster management, and which controller functions have the greatest impact on maintaining application availability and operational efficiency?