style：数据采集-历史记录查询-采集时间默认最近四小时

src/views/iot/historyData/HistorySingleDeviceDialog.vue

@@ -103,6 +103,23 @@ const recordGroups = ref<RecordGroup[]>([])
 
 const collectionTimeRange = ref<string[]>([])
 
+const formatDateTime = (date: Date) => {
+  const pad = (value: number) => String(value).padStart(2, '0')
+  const y = date.getFullYear()
+  const m = pad(date.getMonth() + 1)
+  const d = pad(date.getDate())
+  const h = pad(date.getHours())
+  const mi = pad(date.getMinutes())
+  const s = pad(date.getSeconds())
+  return `${y}-${m}-${d} ${h}:${mi}:${s}`
+}
+
+const buildLastHoursRange = (hours: number) => {
+  const end = new Date()
+  const start = new Date(end.getTime() - hours * 60 * 60 * 1000)
+  return [formatDateTime(start), formatDateTime(end)]
+}
+
 const toGroupMap = (value: any): Record<string, any[]> => {
   if (!value || typeof value !== 'object' || Array.isArray(value)) {
     return {}
@@ -206,6 +223,7 @@ watch(
     if (!visible) {
       return
     }
+    collectionTimeRange.value = buildLastHoursRange(4)
     fetchHistory()
   }
 )