refactor: 前后端目录结构模块化 + v2 优化移植与缺陷修复

前端:
- src/srv/api → src/api，按域分文件夹(auth/cluster/host/storage/deployment/collector)
- 新增 http.ts 引擎(http.get/post/put/delete)，域模块改用语义化调用
- index.html 增加 favicon(匹配应用 logo 的 emerald + Activity 脉冲)

后端分层增强(保留包名):
- 新增 repository/：从 models 拆出 JsonDB 持久化层(InitDB/GetDB/Shutdown/RequestSave)
- 新增 dto/：从 controllers 抽出各域请求契约(带 binding 校验)
- 新增 pkg/crypto、pkg/jwt：从 utils 拆出安全原语(外部 jwt 别名 jwtv5 避免冲突)
- models 只留领域实体 + sanitizer；utils 只留 gin/应用相关(response/errors)

v2 优化移植与缺陷修复:
- 移植密钥分离/SSH TOFU/并发写安全/Loki 生产级配置/Docker 加固
- 修复 deployment.go 并发丢更新、Helm values 重复键、EncryptField 哨兵、loki-gateway 端点等审计缺陷
- 实现真正的优雅关停(main.go http.Server + signal + repository.Shutdown)
- 修复登录契约:后端返回 accessToken，前端 auth.ts/Login.tsx 对齐
- 补 crypto/jwt/repository 单元测试(含并发写回归)

验证: go build/vet/test 全绿；npm run build 通过；登录→鉴权→优雅关停冒烟通过

Co-Authored-By: Claude <noreply@anthropic.com>

frontend/src/api/cluster/index.ts

@@ -0,0 +1,25 @@
+// 集群域 API
+import { http } from '../http';
+import type { PageData, Cluster, ClusterInfo } from '@/types';
+
+export const clusterApi = {
+  list: (page = 1, pageSize = 10) =>
+    http.get<PageData<Cluster>>(`/clusters?page=${page}&pageSize=${pageSize}`),
+
+  get: (id: number) => http.get<Cluster>(`/clusters/${id}`),
+
+  create: (data: {
+    name: string; description?: string; configType?: string;
+    apiServer?: string; kubeconfig?: string; token?: string; context?: string;
+  }) => http.post<Cluster>('/clusters', data),
+
+  update: (id: number, data: Record<string, unknown>) =>
+    http.put<{ message: string }>(`/clusters/${id}`, data),
+
+  remove: (id: number) => http.delete<{ message: string }>(`/clusters/${id}`),
+
+  validate: (id: number) =>
+    http.post<{ message: string }>(`/clusters/${id}/validate`),
+
+  getInfo: (id: number) => http.get<ClusterInfo>(`/clusters/${id}/info`),
+};