refactor: 全局重命名 k8s → kubernetes (前后端+路由+表名+文件)

后端:
  - pkg/k8sclient → pkg/kubernetesclient
  - models/k8s.go → models/kubernetes.go
  - handlers/k8s.go → handlers/kubernetes.go
  - K8sCluster/K8sNode/.. → KubernetesCluster/KubernetesNode/..
  - K8sHandler → KubernetesHandler
  - 路由: /k8s-clusters → /kubernetes-clusters
  - 路由: /k8s/:code/namespace/:ns/... → /kubernetes/:code/namespace/:ns/... (Kuboard风格)
  - 表前缀: container_k8s_ → container_kubernetes_

前端:
  - components/k8s/ → components/kubernetes/
  - K8sClusters → KubernetesClusters
  - K8sWorkloads → KubernetesWorkloads
  - K8sNodes → KubernetesNodes
  - k8sApi → kubernetesApi
  - 路由前缀: /k8s/ → /kubernetes/

测试验证:
✅ /kubernetes/k8s-cluster-liren/namespace/kube-system/deployments → 3 items
✅ /kubernetes/k8s-cluster-liren/namespace/kube-system/pods → 7 items
✅ /kubernetes/k8s-cluster-liren/namespace/kube-system/services → 4 items
✅ /kubernetes/k8s-cluster-liren/namespace/kube-system/configmaps → 6 items
✅ /kubernetes/k8s-cluster-liren/namespace/kube-system/secrets → 1 item
✅ /kubernetes/k8s-cluster-liren/namespaces → 4 items

backend/internal/api/handlers/dashboard.go

@@ -53,16 +53,16 @@ func (h *DashboardHandler) GetStats(c *gin.Context) {
 	stats.ServerStats = serverStats
 
 	// K8s集群统计
-	var k8sStats models.K8sClusterStats
-	h.db.Model(&models.K8sCluster{}).Count(&k8sStats.Total)
-	h.db.Model(&models.K8sCluster{}).Where("status = ?", "healthy").Count(&k8sStats.Healthy)
-	h.db.Model(&models.K8sCluster{}).Where("status = ?", "warning").Count(&k8sStats.Warning)
-	h.db.Model(&models.K8sCluster{}).Where("status = ?", "error").Count(&k8sStats.Error)
+	var k8sStats models.KubernetesClusterStats
+	h.db.Model(&models.KubernetesCluster{}).Count(&k8sStats.Total)
+	h.db.Model(&models.KubernetesCluster{}).Where("status = ?", "healthy").Count(&k8sStats.Healthy)
+	h.db.Model(&models.KubernetesCluster{}).Where("status = ?", "warning").Count(&k8sStats.Warning)
+	h.db.Model(&models.KubernetesCluster{}).Where("status = ?", "error").Count(&k8sStats.Error)
 
 	var totalNodes, totalPods, totalServices int64
-	h.db.Model(&models.K8sNode{}).Count(&totalNodes)
-	h.db.Model(&models.K8sPod{}).Count(&totalPods)
-	h.db.Model(&models.K8sService{}).Count(&totalServices)
+	h.db.Model(&models.KubernetesNode{}).Count(&totalNodes)
+	h.db.Model(&models.KubernetesPod{}).Count(&totalPods)
+	h.db.Model(&models.KubernetesService{}).Count(&totalServices)
 	k8sStats.TotalNodes = totalNodes
 	k8sStats.TotalPods = totalPods
 	k8sStats.TotalServices = totalServices