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>

frontend/src/components/ui/checkbox.tsx

@@ -14,19 +14,23 @@ function Checkbox({
     <CheckboxPrimitive.Root
       data-slot="checkbox"
       className={cn(
-        "peer border-input dark:bg-input/30 data-[state=checked]:bg-primary data-[state=checked]:text-primary-foreground dark:data-[state=checked]:bg-primary data-[state=checked]:border-primary focus-visible:border-ring focus-visible:ring-ring/50 aria-invalid:ring-destructive/20 dark:aria-invalid:ring-destructive/40 aria-invalid:border-destructive size-4 shrink-0 rounded-[4px] border shadow-xs transition-shadow outline-none focus-visible:ring-[3px] disabled:cursor-not-allowed disabled:opacity-50",
+        "peer size-4 shrink-0 rounded-[4px] border shadow-xs outline-none transition-colors",
+        "border-[var(--dg-border)] bg-[var(--dg-bg-tertiary)]",
+        "data-[state=checked]:bg-blue-600 data-[state=checked]:border-blue-600 data-[state=checked]:text-white",
+        "focus-visible:ring-2 focus-visible:ring-[var(--dg-blue)]/40",
+        "disabled:cursor-not-allowed disabled:opacity-50",
         className
       )}
       {...props}
     >
       <CheckboxPrimitive.Indicator
         data-slot="checkbox-indicator"
-        className="grid place-content-center text-current transition-none"
+        className="flex items-center justify-center text-white"
       >
-        <CheckIcon className="size-3.5" />
+        <CheckIcon className="size-3.5 stroke-[3]" />
       </CheckboxPrimitive.Indicator>
     </CheckboxPrimitive.Root>
   )
 }
 
-export { Checkbox }
+export { Checkbox }

frontend/src/components/ui/switch.tsx

@@ -13,7 +13,12 @@ function Switch({
     <SwitchPrimitive.Root
       data-slot="switch"
       className={cn(
-        "peer data-[state=checked]:bg-primary data-[state=unchecked]:bg-input focus-visible:border-ring focus-visible:ring-ring/50 dark:data-[state=unchecked]:bg-input/80 inline-flex h-[1.15rem] w-8 shrink-0 items-center rounded-full border border-transparent shadow-xs transition-all outline-none focus-visible:ring-[3px] disabled:cursor-not-allowed disabled:opacity-50",
+        "peer inline-flex h-[1.15rem] w-8 shrink-0 items-center rounded-full border transition-all outline-none",
+        "data-[state=checked]:bg-primary data-[state=checked]:border-primary",
+        "data-[state=unchecked]:bg-[var(--dg-bg-tertiary)] data-[state=unchecked]:border-[var(--dg-border-hover)]",
+        "data-[state=unchecked]:shadow-[inset_0_1px_2px_rgba(0,0,0,0.18)] dark:data-[state=unchecked]:shadow-[inset_0_1px_3px_rgba(0,0,0,0.45)]",
+        "focus-visible:border-ring focus-visible:ring-ring/50 focus-visible:ring-[3px]",
+        "disabled:cursor-not-allowed disabled:opacity-50",
         className
       )}
       {...props}
@@ -21,7 +26,9 @@ function Switch({
       <SwitchPrimitive.Thumb
         data-slot="switch-thumb"
         className={cn(
-          "bg-[var(--dg-bg-primary)] pointer-events-none block size-4 rounded-full ring-0 transition-transform data-[state=checked]:translate-x-[calc(100%-2px)] data-[state=unchecked]:translate-x-0"
+          "pointer-events-none block size-4 rounded-full ring-0 transition-transform shadow-sm",
+          "bg-[var(--dg-bg-primary)] data-[state=checked]:translate-x-[calc(100%-2px)]",
+          "data-[state=unchecked]:translate-x-0 data-[state=unchecked]:bg-[var(--dg-text-secondary)]",
         )}
       />
     </SwitchPrimitive.Root>