chore: remove unused ClusterHealth types

Remove internal/models/cluster.go containing ClusterHealth and
ClusterNodeStatus types that were never used in the codebase.

internal/models/cluster.go

@@ -1,17 +0,0 @@
-package models
-
-// ClusterHealth represents the health status of a cluster
-type ClusterHealth struct {
-	Name             string              `json:"name"`
-	TotalNodes       int                 `json:"totalNodes"`
-	OnlineNodes      int                 `json:"onlineNodes"`
-	OfflineNodes     int                 `json:"offlineNodes"`
-	HealthPercentage float64             `json:"healthPercentage"`
-	NodeStatuses     []ClusterNodeStatus `json:"nodeStatuses"`
-}
-
-// ClusterNodeStatus represents the status of a single node in a cluster
-type ClusterNodeStatus struct {
-	Endpoint string `json:"endpoint"`
-	Online   bool   `json:"online"`
-}