feat(k8s): M2 Pod Metrics 详情页接入 — ListPods 注入 metrics

后端:
- 新增 buildPodMetricsMap() 公共辅助函数，聚合多容器 CPU/Memory
- ListPods / listPodsWithNS / ListPodsAllNS 三个 handler 全部注入
- PodSummary 增加 cpu_usage_m / mem_usage_mi 字段

前端:
- KubernetesWorkloads Pod 表格增加 CPU/内存列
- NamespaceResourcePage Pod 表格增加 CPU/内存列

验证:
- 17 个 Pod 全部返回真实 metrics (argocd/demo-jar)
- curl /kubernetes-clusters/1/pods → cpu_usage_m='2m' mem_usage_mi='61Mi'

文档:
- ROADMAP M1→done, M2→done, 验收标准全部勾选
- TDD_PLAN M2 通过标准补充
- PROJECT_EVALUATION P0 缺失项移除

frontend/src/components/kubernetes/NamespaceResourcePage.tsx

@@ -64,7 +64,7 @@ const RESOURCE_CONFIG: Record<ResourceType, {
   },
   pods: {
     title: 'Pods', subtitle: 'Pod 实例运行状态', icon: Container,
-    columns: ['名称', '命名空间', '状态', '节点', '重启', '镜像', '操作'],
+    columns: ['名称', '命名空间', '状态', '节点', 'CPU', '内存', '重启', '镜像', '操作'],
     renderRow: (p, opts) => {
       const statusMap: Record<string, string> = { Running: 'bg-emerald-500/20 text-emerald-400 border-emerald-500/30', Pending: 'bg-yellow-500/20 text-yellow-400 border-yellow-500/30', Failed: 'bg-red-500/20 text-red-400 border-red-500/30' };
       return (
@@ -73,6 +73,8 @@ const RESOURCE_CONFIG: Record<ResourceType, {
           <TableCell><Badge variant="outline" className="border-slate-700 text-slate-400">{p.namespace}</Badge></TableCell>
           <TableCell><Badge className={statusMap[p.status] || 'bg-slate-500/20 text-slate-400'}>{p.status || 'Unknown'}</Badge></TableCell>
           <TableCell className="text-sm text-slate-400">{p.node_name || '-'}</TableCell>
+          <TableCell className="text-sm text-cyan-400">{p.cpu_usage_m || '-'}</TableCell>
+          <TableCell className="text-sm text-amber-400">{p.mem_usage_mi || '-'}</TableCell>
           <TableCell className={(p.restart_count > 0 ? 'text-yellow-400' : 'text-slate-500')}>{p.restart_count || 0}</TableCell>
           <TableCell className="text-xs text-slate-500 max-w-[200px] truncate">{p.image || '-'}</TableCell>
           <TableCell><Button variant="ghost" size="icon" className="h-7 w-7 text-slate-400 hover:text-blue-400" title="查看YAML" onClick={() => opts.onYaml?.(p.name)}><FileCode className="h-3.5 w-3.5" /></Button></TableCell>