feat: AI预测分析接入真实后端数据 + 修复CloudBilling文件损坏

- AIPredictiveAnalytics: 替换3组硬编码mock为实时数据驱动预测
  - 指标预测: 基于dashboard metrics时序数据(cpu/memory/disk)线性回归计算斜率与R²
  - 容量规划: 基于日均增长率推算阈值触及时间(天),动态生成AI扩容建议
  - 异常预测: 基于告警规则阈值+当前趋势+事件频率计算异常触发概率
  - 概览卡片数据驱动化(置信度基于R²拟合度,高风险/容量预警计数实时计算)
- CloudBilling.tsx: 修复read_file导致的行号前缀损坏(501行全部含N|前缀)

frontend/src/components/monitor/dashboard/GrafanaDashboard.tsx

@@ -20,6 +20,7 @@ import { Label } from '@/components/ui/label';
 import { Switch } from '@/components/ui/switch';
 import { Separator } from '@/components/ui/separator';
 import { toast } from 'sonner';
+import { useConfirm } from '@/components/ui/confirm-dialog';
 import { dashboardApi } from '@/services/api';
 
 interface Dashboard {
@@ -73,6 +74,7 @@ interface Datasource {
 }
 
 const GrafanaDashboard: React.FC = () => {
+  const _confirm = useConfirm();
   const [dashboards, setDashboards] = useState<Dashboard[]>([]);
   const [datasources, setDatasources] = useState<Datasource[]>([]);
   const [activeDashboard, setActiveDashboard] = useState<Dashboard | null>(null);
@@ -201,7 +203,7 @@ const GrafanaDashboard: React.FC = () => {
   };
 
   const handleDeleteDashboard = async (id: string) => {
-    if (!confirm('确定删除此仪表盘吗？')) return;
+    { const ok = await _confirm({ title: '删除仪表盘', description: '确定删除此仪表盘吗？', confirmText: '删除', variant: 'destructive' }); if (!ok) return; }
     try {
       await dashboardApi.deleteDashboard(id);
       toast.success('删除成功');