fix(mileage): 导出保留里程小数

src/modules/mileage/xlsx-export.ts

@@ -20,9 +20,9 @@ function mileageCell(v: MonitoringVehicle, kind: 'today' | 'total'): string | nu
   if (kind === 'today') {
     // 当日未对接但有历史累计，视作今日 0；只有完全无数据才标「未对接」
     if (!v.isDataSynced && v.totalKm == null) return '未对接';
-    return Math.max(0, Math.round(v.dailyKm || 0));
+    return Math.max(0, v.dailyKm || 0);
   }
-  return v.totalKm != null ? Math.round(v.totalKm) : '未对接';
+  return v.totalKm != null ? v.totalKm : '未对接';
 }
 
 export function exportMileageXlsx(vehicles: MonitoringVehicle[], ctx: ExportContext): void {
@@ -57,6 +57,13 @@ export function exportMileageXlsx(vehicles: MonitoringVehicle[], ctx: ExportCont
 
   ws['!freeze'] = { xSplit: 0, ySplit: 1 } as never;
 
+  for (let r = 1; r < data.length; r++) {
+    for (const c of [7, 8]) {
+      const ref = XLSX.utils.encode_cell({ r, c });
+      if (ws[ref]?.t === 'n') ws[ref].z = '0.##########';
+    }
+  }
+
   // 表头样式（在客户端 SheetJS 社区版仅基本样式生效）
   for (let c = 0; c < HEADERS.length; c++) {
     const ref = XLSX.utils.encode_cell({ r: 0, c });