feat(admin): enforce monitoring page permissions

app/admin/routers/device_liveness.py

@@ -2,7 +2,7 @@
 
 数据源 device_liveness 表(心跳 last_heartbeat_at + liveness_state + kill_alert_pending,
 见 app/models/device.py)。在线/掉线、掉线时长由 repo 按 HEARTBEAT_TIMEOUT_MINUTES 阈值派生。
-纯读:无写、无审计。任意登录管理员可看(同大盘/设备管理,无角色门)。
+纯读:无写、无审计。需要 device-liveness 页面权限。
 """
 from __future__ import annotations
 
@@ -10,7 +10,7 @@ from typing import Annotated
 
 from fastapi import APIRouter, Depends, Query
 
-from app.admin.deps import AdminDb, get_current_admin
+from app.admin.deps import AdminDb, require_page
 from app.admin.repositories import queries
 from app.admin.schemas.common import CursorPage
 from app.admin.schemas.device import DeviceLivenessItem, DeviceLivenessStats
@@ -18,7 +18,7 @@ from app.admin.schemas.device import DeviceLivenessItem, DeviceLivenessStats
 router = APIRouter(
     prefix="/admin/api/device-liveness",
     tags=["admin-device-liveness"],
-    dependencies=[Depends(get_current_admin)],
+    dependencies=[Depends(require_page("device-liveness"))],
 )