feat(monitor): U13 主机监控大屏挂载 — HostMonitorDashboard 死代码复活为 /host-dashboard 路由 + 监控菜单

- App.tsx: 新增 HostMonitorDashboard lazy import + Route path=host-dashboard
- Sidebar.tsx: 监控告警菜单新增「主机大屏」子项 (menu.hostDashboard, agent:monitor 权限)
- Breadcrumb.tsx: 新增 host-dashboard 路由段映射
- i18n: zh-CN/en-US 新增 menu.hostDashboard + breadcrumb.hostDashboard (主机大屏/Host Dashboard), 7556 keys 对齐
- 复用已有 monitor:hostDashboard.* 23 翻译键 (AgentMonitor/MiddlewareMonitor/data-table 共享)
- ROADMAP.md: 新增 U13 模块记录 + 状态追踪表
- PROJECT_EVALUATION.md: 清除 3.3 死代码技术债 + U12 过时数字 + 监控模块补充主机大屏
- TDD_PLAN.md: 新增 P3-U13 验证用例和通过标准

验证: tsc -b=0, npm build✓(17.50s), ESLint errors=0, 17/17 集成回归通过, Docker healthy

frontend/src/locales/en-US.json

@@ -563,6 +563,7 @@
     "monitor": "Monitoring",
     "grafana": "Dashboards",
     "resourceMonitor": "Resource Monitor",
+    "hostDashboard": "Host Dashboard",
     "trace": "Tracing",
     "alertCenter": "Alert Center",
     "datasources": "Datasources",
@@ -7995,6 +7996,7 @@
     "datasources": "Data Sources",
     "dashboards": "Dashboards",
     "hostMonitor": "Host Monitor",
+    "hostDashboard": "Host Dashboard",
     "alerts": "Alerts",
     "approval": "Requests",
     "approvalResource": "Resource Request",

frontend/src/locales/zh-CN.json

@@ -563,6 +563,7 @@
     "monitor": "监控中心",
     "grafana": "监控大屏",
     "resourceMonitor": "资源监控",
+    "hostDashboard": "主机大屏",
     "trace": "链路追踪",
     "alertCenter": "告警中心",
     "datasources": "数据源",
@@ -7995,6 +7996,7 @@
     "datasources": "数据源",
     "dashboards": "监控大屏",
     "hostMonitor": "主机监控",
+    "hostDashboard": "主机大屏",
     "alerts": "监控告警",
     "approval": "资源申请",
     "approvalResource": "资源申请",