feat(timer): 新增 run_type 调度、host_id 投递和日志清理

T7: TimerBase shouldExecuteTask() - main/auto/all/manual/disabled modes
    with two-phase DB row lock for auto mode
T8: TimerControllerBase - host_id param, logStart/logEnd methods
    TimerServiceBase - inject host_id into site URLs
T9: TimerLogClean command - php think admin:timer:log:clean --days=30

app/admin/model/SystemTimerLog.php

@@ -0,0 +1,12 @@
+<?php
+
+namespace app\admin\model;
+
+use think\Model;
+
+class SystemTimerLog extends Model
+{
+    protected $name = 'system_timer_log';
+
+    protected $autoWriteTimestamp = true;
+}