feat(k8s): A1 K8s 双路由体系统一 — code 路由为主, ID 路由标记 deprecated

后端:
- 新增 4 条 all-NS code 路由: services/ingresses/cronjobs/nodes
- ListNodes 改用 getK8sClientByCode (兼容 ID+code)
- ID 域资源路由标记 // Deprecated

前端:
- clusterApi/nodeApi/workloadApi 资源方法迁移到 code 路由
- KubernetesClusterDetail/TopologyView/KubernetesNodes 组件从 cluster.id 迁移到 cluster.code
- 修复潜在 bug: ClusterOverviewPage 曾将 code 传给 ID-based getNodes

验证: 16/16 API 测试通过 (7 新 code 路由 + 3 旧 ID 兼容 + 6 回归)
go build=✅ tsc -b=✅ npm build=✅

frontend/src/components/kubernetes/KubernetesNodes.tsx

@@ -26,7 +26,7 @@ export function KubernetesNodes() {
       const res: JsonData = await kubernetesApi.getClusters();
       const list = res?.list || [];
       setClusters(list);
-      if (list.length > 0 && !selectedCluster) setSelectedCluster(String(list[0].id));
+      if (list.length > 0 && !selectedCluster) setSelectedCluster(String(list[0].code || list[0].id));
     } catch { setClusters([]); }
   }, []);
 
@@ -72,7 +72,7 @@ export function KubernetesNodes() {
             </SelectTrigger>
             <SelectContent className="bg-slate-800 border-slate-700">
               {clusters.map((c) => (
-                <SelectItem key={c.id} value={String(c.id)}>{c.name}</SelectItem>
+                <SelectItem key={c.id} value={String(c.code || c.id)}>{c.name}</SelectItem>
               ))}
             </SelectContent>
           </Select>