feat(timer): 新增定时器配置、日志和主机的后台管理界面

T10: TimerConfig CURD - task management with run_type/status editing,
     manual trigger button, task_name read-only, no add/delete
T11: TimerLog CURD - read-only log viewer with filters and color badges
T12: Host list enhanced - is_master column, setMaster button

extend/base/admin/model/SystemHostBase.php

@@ -26,4 +26,6 @@ class SystemHostBase extends TimeModel
     protected $deleteTime = false;
 
     public const SELECT_LIST_STATUS = ['0' => '离线', '1' => '在线'];
+
+    public const SELECT_LIST_IS_MASTER = ['0' => '从节点', '1' => '主节点'];
 }