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

frontend/src/App.tsx

@@ -12,10 +12,10 @@ import { DomainManager } from '@/components/cloud/DomainManager';
 import { RegionManager } from '@/components/cloud/RegionManager';
 import { PlatformManager } from '@/components/cloud/PlatformManager';
 import { CloudBilling } from '@/components/cloud/CloudBilling';
-import { K8sClusters } from '@/components/k8s/K8sClusters';
-import { K8sNodes } from '@/components/k8s/K8sNodes';
-import { K8sWorkloads } from '@/components/k8s/K8sWorkloads';
-import { TopologyView } from '@/components/k8s/TopologyView';
+import { KubernetesClusters } from '@/components/kubernetes/KubernetesClusters';
+import { KubernetesNodes } from '@/components/kubernetes/KubernetesNodes';
+import { KubernetesWorkloads } from '@/components/kubernetes/KubernetesWorkloads';
+import { TopologyView } from '@/components/kubernetes/TopologyView';
 import { AlertManager } from '@/components/monitor/AlertManager';
 import { AppReleaseManager } from '@/components/deploy/AppRelease';
 import { ApprovalFlowManager } from '@/components/approval/ApprovalFlow';
@@ -65,9 +65,9 @@ function App() {
             <Route path="cloud-billing" element={<CloudBilling />} />
             {/* 资源监控（Agent 指标 + 中间件 + SNMP + 拨测） */}
             <Route path="monitor-center" element={<MonitorCenter />} />
-            <Route path="clusters" element={<K8sClusters />} />
-            <Route path="nodes" element={<K8sNodes />} />
-            <Route path="workloads" element={<K8sWorkloads />} />
+            <Route path="clusters" element={<KubernetesClusters />} />
+            <Route path="nodes" element={<KubernetesNodes />} />
+            <Route path="workloads" element={<KubernetesWorkloads />} />
             <Route path="topology" element={<TopologyView />} />
             {/* 应用发布 */}
             <Route path="pipelines" element={<PipelineManager />} />