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

TDD_PLAN.md

@@ -1088,3 +1088,66 @@ python3 ../tests/integration_test.py --host 127.0.0.1 --port 8080
 - [x] U4: KubernetesClusterDetail 非注释 CJK = 0
 - [x] U5: TopologyView 非注释 CJK = 0
 - [x] U6: 17/17 集成回归测试通过
+
+---
+
+## P3-U13: 主机监控大屏挂载（HostMonitorDashboard 死代码复活）
+
+### 验证用例
+
+```bash
+# U1: 路由配置存在
+grep -c 'host-dashboard' /srv/aiops/frontend/src/App.tsx
+# 期望: >= 2 (lazy import + Route)
+
+# U2: Sidebar 菜单项存在
+grep -c 'host-dashboard' /srv/aiops/frontend/src/components/layout/Sidebar.tsx
+# 期望: >= 1
+
+# U3: Breadcrumb 映射存在
+grep -c 'host-dashboard' /srv/aiops/frontend/src/components/layout/Breadcrumb.tsx
+# 期望: >= 1
+
+# U4: i18n 翻译键存在且对齐
+python3 -c "
+import json
+zh = json.load(open('/srv/aiops/frontend/src/locales/zh-CN.json', encoding='utf-8'))
+en = json.load(open('/srv/aiops/frontend/src/locales/en-US.json', encoding='utf-8'))
+assert zh['menu']['hostDashboard'] == '主机大屏'
+assert en['menu']['hostDashboard'] == 'Host Dashboard'
+assert zh['breadcrumb']['hostDashboard'] == '主机大屏'
+assert en['breadcrumb']['hostDashboard'] == 'Host Dashboard'
+print('✅ i18n keys aligned')
+"
+
+# U5: TypeScript 编译零错误
+cd /srv/aiops/frontend && npx tsc -b 2>&1 | tail -3
+# 期望: 退出码 0
+
+# U6: Vite 构建
+npm run build 2>&1 | tail -3
+# 期望: built in Ns
+
+# U7: ESLint 无新增 errors
+npx eslint src/ --format json 2>/dev/null | python3 -c "
+import json, sys
+data = json.load(sys.stdin)
+errors = sum(1 for r in data for m in r.get('messages', []) if m.get('severity') == 2)
+assert errors == 0, f'{errors} errors'
+print('✅ ESLint errors=0')
+"
+
+# U8: 集成回归测试
+python3 /srv/aiops/tests/integration_test.py --host 127.0.0.1 --port 8080 | tail -3
+# 期望: 17/17 passed
+```
+
+### 通过标准
+- [x] U1: App.tsx 路由配置存在（lazy import + Route path="host-dashboard"）
+- [x] U2: Sidebar 监控菜单含「主机大屏」项
+- [x] U3: Breadcrumb 路由映射存在
+- [x] U4: zh/en 翻译键对齐（menu.hostDashboard + breadcrumb.hostDashboard）
+- [x] U5: `tsc -b` 零错误
+- [x] U6: `npm run build` 零错误（✓ built in 17.50s）
+- [x] U7: ESLint errors=0（无新增）
+- [x] U8: 17/17 集成回归测试通过（零回归）