refactor(frontend): services/api 迁至 src/api，http 迁至 utils/request

对齐 Vue 后台惯例：
- src/api/          域 API（原 services/api）
- src/utils/request.ts  HTTP 封装（原 services/http.ts）
- src/utils/export.ts  客户端导出工具
- src/utils/index.ts   工具统一出口

全局导入改为 @/api 与 @/utils/request，tsc + build 通过。

frontend/src/components/kubernetes/ResourceVisualEditor.tsx

@@ -10,7 +10,7 @@ import { Label } from '@/components/ui/label';
 import { Textarea } from '@/components/ui/textarea';
 import { Select, SelectContent, SelectItem, SelectTrigger, SelectValue } from '@/components/ui/select';
 import { useToast } from '@/hooks/use-toast';
-import { kubernetesApi } from '@/services/api';
+import { kubernetesApi } from '@/api';
 import CodeMirror from '@uiw/react-codemirror';
 import { yaml } from '@codemirror/lang-yaml';
 import { oneDark } from '@codemirror/theme-one-dark';