feat(server): 添加后端入口和统一响应格式测试路由

- 新增 server/cmd/server/main.go 作为服务入口
- 注册 /api/v1/test/* 测试端点，覆盖成功、业务错误、HTTP 错误、超时等场景
- 加载 Logger 和 Recovery 中间件
- 修复 recovery.go 未使用的 net/http 导入
- 更新 go.mod/go.sum 依赖

frontend/components.d.ts

@@ -12,12 +12,14 @@ declare module 'vue' {
     AppSidebar: typeof import('./src/components/Layout/AppSidebar.vue')['default']
     AuditLogTable: typeof import('./src/components/AuditLogTable.vue')['default']
     ElButton: typeof import('element-plus/es')['ElButton']
+    ElDivider: typeof import('element-plus/es')['ElDivider']
     ElForm: typeof import('element-plus/es')['ElForm']
     ElFormItem: typeof import('element-plus/es')['ElFormItem']
     ElIcon: typeof import('element-plus/es')['ElIcon']
     ElInput: typeof import('element-plus/es')['ElInput']
     ElOption: typeof import('element-plus/es')['ElOption']
     ElSelect: typeof import('element-plus/es')['ElSelect']
+    ElSpace: typeof import('element-plus/es')['ElSpace']
     RouterLink: typeof import('vue-router')['RouterLink']
     RouterView: typeof import('vue-router')['RouterView']
     SubsystemCard: typeof import('./src/components/SubsystemCard.vue')['default']