feat: 监控告警体系统一重构 + 自动化任务调度引擎 + 监控大屏拆分

告警中心
- 新增统一告警(alert_unified)、监控告警规则(monitor_alert_rule)、指标目录(alert_metric_catalog)
- 通知策略与消息分发(alert_notify_policy/dispatch/message)、静默规则
- 告警引擎按阈值/SNMP 拆分(alert_engine_monitor/snmp)

监控采集
- SNMP 常量/模板与历史指标(snmp templates/constants、snmp_metrics_history、snmp_collect)
- 中间件监控 Redis 采集与种子(middleware_monitor_redis/seed)
- 站点探测 pkg(siteprobe) + 站点视图(site_view)

自动化任务
- cron 调度器(cronscheduler)、脚本运行器(scriptrunner)、系统任务(systask)及运行记录(cron_job_run、system_task)

审计与凭证
- 审计设置(audit_setting) + 历史清理(auditcleaner)

前端
- 监控页面(host/middleware/site/snmp)拆分为子模块并大屏化
- 告警中心多 Tab(规则/指标目录/通知策略/静默)、任务管理组件重构、Agent CLI Markdown 渲染
- 移除旧脚本卡片/详情/日志组件，统一为 ScriptTable/ScriptCodeEditor/TerminalOutput

Co-Authored-By: Claude <noreply@anthropic.com>

backend/controller/automation_cron.go

@@ -1,13 +1,10 @@
 package controller
 
 import (
-	"fmt"
 	"net/http"
 	"strconv"
-	"time"
 
 	"ezops/model"
-	"ezops/pkg/remoteexec"
 
 	"github.com/gin-gonic/gin"
 )
@@ -294,113 +291,16 @@ func (h *AutomationHandler) ToggleCronJob(c *gin.Context) {
 // @Router /cron-jobs/{id}/execute [post]
 func (h *AutomationHandler) ExecuteCronJob(c *gin.Context) {
 	id, _ := strconv.Atoi(c.Param("id"))
-
-	var job model.CronJob
-	if err := h.db.First(&job, id).Error; err != nil {
+	execution, err := RunCronJobByID(h.db, uint(id))
+	if err != nil {
 		c.JSON(http.StatusNotFound, model.Response{
 			Code:    404,
-			Message: "定时任务不存在",
+			Message: err.Error(),
 		})
 		return
 	}
-
-	// Resolve the content to execute. For type=script, load the linked Script.
-	content := job.Content
-	scriptType := job.Type // shell | python | command | script
-	if scriptType == "command" {
-		scriptType = "shell" // one-liner commands run via bash
-	}
-	if job.Type == "script" && job.ScriptID != nil {
-		var script model.Script
-		if err := h.db.First(&script, *job.ScriptID).Error; err == nil {
-			content = script.Content
-			scriptType = script.Type
-			h.db.Model(&script).UpdateColumn("run_count", script.RunCount+1)
-		}
-	}
-
-	now := time.Now()
-	execution := model.TaskExecution{
-		TaskType:   "cron",
-		TaskID:     uint(id),
-		TaskName:   job.Name,
-		Status:     "running",
-		TargetType: job.TargetType,
-		Targets:    job.Targets,
-		StartedAt:  &now,
-	}
-	if err := h.db.Create(&execution).Error; err != nil {
-		c.JSON(http.StatusInternalServerError, model.Response{
-			Code:    500,
-			Message: "创建执行记录失败",
-		})
-		return
-	}
-
-	var output string
-	var exitCode int
-	var duration int
-	status := "success"
-
-	// 根据 TargetType 决定执行方式 // Logan.Li
-	if job.TargetType != "" && job.TargetType != "local" && job.Targets != "" {
-		// 远程目标执行 — 通过 SSH 并发执行
-		remoteResults, remoteErr := ExecuteCronOnTargets(h.db, job, scriptType, content, job.Timeout)
-		duration = int(time.Since(now).Milliseconds())
-
-		if remoteErr != nil {
-			output = fmt.Sprintf("远程执行调度失败: %v", remoteErr)
-			exitCode = -1
-			status = "failed"
-		} else {
-			// 格式化远程执行结果
-			output = remoteexec.FormatExecResults(remoteResults)
-			// 任意一台失败则整体标记为 failed
-			for _, r := range remoteResults {
-				if !r.Success {
-					status = "failed"
-					exitCode = -1
-					break
-				}
-			}
-		}
-	} else {
-		// 本地执行
-		output, exitCode, duration = runLocal(scriptType, content, job.Timeout)
-		if exitCode != 0 {
-			status = "failed"
-		}
-	}
-
-	finishedAt := time.Now()
-
-	h.db.Model(&execution).Updates(map[string]interface{}{
-		"status":      status,
-		"output":      output,
-		"duration":    duration,
-		"finished_at": finishedAt,
-	})
-
-	// Update cron job statistics.
-	statsUpdates := map[string]interface{}{
-		"last_run_at": now,
-		"last_status": status,
-		"run_count":   job.RunCount + 1,
-	}
-	if status == "success" {
-		statsUpdates["success_count"] = job.SuccessCount + 1
-	} else {
-		statsUpdates["fail_count"] = job.FailCount + 1
-	}
-	h.db.Model(&job).Updates(statsUpdates)
-
-	execution.Output = output
-	execution.Status = status
-	execution.Duration = duration
-	execution.FinishedAt = &finishedAt
-
 	msg := "执行成功"
-	if status == "failed" {
+	if execution.Status == "failed" {
 		msg = "执行失败"
 	}
 	c.JSON(http.StatusOK, model.Response{