feat(platform): diagnose source consistency

vehicle-data-platform/apps/api/internal/platform/service.go

@@ -376,9 +376,53 @@ func buildVehicleSourceConsistency(statuses []VehicleSourceStatus, realtime []Re
 	if hasTime {
 		consistency.SourceTimeDeltaSeconds = maxTime.Sub(minTime).Seconds()
 	}
+	applyVehicleSourceConsistencyDiagnosis(consistency)
 	return consistency
 }
 
+func applyVehicleSourceConsistencyDiagnosis(consistency *VehicleSourceConsistency) {
+	if consistency == nil {
+		return
+	}
+	switch {
+	case consistency.SourceCount <= 0:
+		consistency.Status = "no_source"
+		consistency.Severity = "warning"
+		consistency.Title = "暂无来源"
+		consistency.Detail = "当前车辆没有可用于交叉校验的数据来源。"
+	case consistency.SourceCount == 1:
+		consistency.Status = "single_source"
+		consistency.Severity = "warning"
+		consistency.Title = "单一来源"
+		consistency.Detail = "当前车辆只有一个数据来源，无法做跨来源一致性校验。"
+	case consistency.OnlineSourceCount <= 0:
+		consistency.Status = "offline"
+		consistency.Severity = "error"
+		consistency.Title = "全部来源离线"
+		consistency.Detail = sourceCoverageDetail(consistency.SourceCount, consistency.OnlineSourceCount, "无法判断实时一致性。")
+	case consistency.OnlineSourceCount < consistency.SourceCount:
+		consistency.Status = "degraded"
+		consistency.Severity = "warning"
+		consistency.Title = "部分来源离线"
+		consistency.Detail = sourceCoverageDetail(consistency.SourceCount, consistency.OnlineSourceCount, "车辆服务可用但需要关注离线来源。")
+	case consistency.MileageDeltaKm > 5:
+		consistency.Status = "mileage_divergent"
+		consistency.Severity = "warning"
+		consistency.Title = "里程差异偏大"
+		consistency.Detail = "多个来源的实时总里程差异超过 5 km，请核对来源解析、单位和上报时间。"
+	case consistency.SourceTimeDeltaSeconds > 300:
+		consistency.Status = "time_divergent"
+		consistency.Severity = "warning"
+		consistency.Title = "来源时间差偏大"
+		consistency.Detail = "多个来源的最新上报时间相差超过 5 分钟，请关注转发延迟或链路断点。"
+	default:
+		consistency.Status = "consistent"
+		consistency.Severity = "ok"
+		consistency.Title = "来源一致"
+		consistency.Detail = sourceCoverageDetail(consistency.SourceCount, consistency.OnlineSourceCount, "多源实时状态一致。")
+	}
+}
+
 func parseVehicleServiceTime(value string) (time.Time, bool) {
 	value = strings.TrimSpace(value)
 	if value == "" {
@@ -477,6 +521,7 @@ func applyVehicleServiceOverviewDerivedFields(overview *VehicleServiceOverview,
 		OnlineSourceCount: overview.OnlineSourceCount,
 		Scope:             "all_sources",
 	}
+	applyVehicleSourceConsistencyDiagnosis(overview.SourceConsistency)
 }
 
 func statusesForOverview(overview *VehicleServiceOverview) []VehicleSourceStatus {