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/api/monitor/alert-metrics.ts

@@ -0,0 +1,69 @@
+// 监控指标目录 & 统一告警 API // Logan.Li
+
+import { http } from '@/utils/request';
+
+export interface MetricCatalogItem {
+  key: string;
+  label: string;
+  unit: string;
+  type: string;
+  default_op: string;
+  default_warn: number;
+  default_crit: number;
+  min: number;
+  max: number;
+  collect_source: string;
+  description: string;
+  operators: string[];
+}
+
+export interface MetricCatalogCategory {
+  id: 'host' | 'middleware' | 'snmp' | 'site';
+  label: string;
+  description: string;
+  metrics: MetricCatalogItem[];
+}
+
+export interface UnifiedAlertRule {
+  id: number;
+  category: 'host' | 'middleware' | 'snmp' | 'site';
+  name: string;
+  target?: string;
+  target_id?: number;
+  metric: string;
+  operator: string;
+  threshold: number;
+  enabled: boolean;
+  severity: string;
+  description?: string;
+  rule_type: 'agent' | 'monitor';
+  port?: number;
+}
+
+export const alertMetricsApi = {
+  getCatalog: () =>
+    http.get<{ categories: MetricCatalogCategory[] }>('/alerts/metric-catalog'),
+
+  getUnifiedAlerts: (params?: {
+    page?: number; page_size?: number;
+    status?: string; severity?: string; source_type?: string;
+  }) => http.get<{ list: unknown[]; total: number; stats: Record<string, number> }>('/alerts/unified', params),
+
+  getUnifiedRules: (category?: string) =>
+    http.get<{ list: UnifiedAlertRule[]; total: number }>('/alerts/unified-rules', { category: category || 'all' }),
+
+  createMonitorRule: (data: Record<string, unknown>) =>
+    http.post('/alerts/monitor-rules', data),
+
+  updateMonitorRule: (id: number, data: Record<string, unknown>) =>
+    http.put(`/alerts/monitor-rules/${id}`, data),
+
+  deleteMonitorRule: (id: number) =>
+    http.delete(`/alerts/monitor-rules/${id}`),
+
+  monitorQuickSetup: (category?: string) =>
+    http.post('/alerts/monitor-quick-setup', { category: category || 'all' }),
+
+  resolveUnified: (source: string, id: number) =>
+    http.post(`/alerts/unified/${source}/${id}/resolve`),
+};