feat(web): show active sandbox details in Box status popover

Display sandbox count and a detailed list of active sessions including
session ID, image, backend, resources (CPU/memory), network mode, and
last used time. Fetched from GET /api/v1/box/sessions in parallel.
Includes i18n for all 8 supported languages.

web/src/i18n/locales/zh-Hans.ts

@@ -452,7 +452,12 @@ const zhHans = {
     boxUnavailable: '不可用',
     boxBackend: '后端',
     boxProfile: '配置',
+    boxSandboxes: '沙箱数',
     boxErrors: '错误数',
+    boxSessionImage: '镜像',
+    boxSessionBackend: '后端',
+    boxSessionResources: '资源',
+    boxSessionNetwork: '网络',
     boxStatusLoadFailed: '加载 Box 状态失败',
     failedToGetDebugInfo: '获取调试信息失败',
     copiedToClipboard: '已复制到剪贴板',