fix: CSV экспорт — bundle (1 PN → N LOT) разворачивается в отдельные строки

buildPricingExportBlock теперь создаёт одну строку на каждый LOT mapping,
а не одну строку на BOM-строку. BOM-цена ставится только в первую подстроку
(как vendorOrig в фронтенде). Добавлен computeSingleLotTotal, удалён
неиспользуемый formatLotDisplay.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

internal/services/export.go

@@ -388,17 +388,37 @@ func (s *ExportService) buildPricingExportBlock(cfg *models.Configuration, opts
 				description = componentDescriptions[rowMappings[0].LotName]
 			}
 
-			pricingRow := ProjectPricingExportRow{
+			if len(rowMappings) == 0 {
-				LotDisplay:  formatLotDisplay(rowMappings),
+				block.Rows = append(block.Rows, ProjectPricingExportRow{
-				VendorPN:    row.VendorPartnumber,
+					LotDisplay:  "н/д",
-				Description: description,
+					VendorPN:    row.VendorPartnumber,
-				Quantity:    exportPositiveInt(row.Quantity, 1),
+					Description: description,
-				BOMTotal:    vendorRowTotal(row),
+					Quantity:    exportPositiveInt(row.Quantity, 1),
-				Estimate:    computeMappingTotal(priceMap, rowMappings, row.Quantity, func(p pricingLevels) *float64 { return p.Estimate }),
+					BOMTotal:    vendorRowTotal(row),
-				Stock:       computeMappingTotal(priceMap, rowMappings, row.Quantity, func(p pricingLevels) *float64 { return p.Stock }),
+				})
-				Competitor:  computeMappingTotal(priceMap, rowMappings, row.Quantity, func(p pricingLevels) *float64 { return p.Competitor }),
+				continue
+			}
+
+			// One export row per LOT mapping so that bundles (1 PN → N LOTs) appear
+			// as separate lines, matching the frontend pricing table layout.
+			pnQty := exportPositiveInt(row.Quantity, 1)
+			for i, mapping := range rowMappings {
+				lotQty := pnQty * mapping.QuantityPerPN
+				var bomTotal *float64
+				if i == 0 {
+					bomTotal = vendorRowTotal(row)
+				}
+				block.Rows = append(block.Rows, ProjectPricingExportRow{
+					LotDisplay:  mapping.LotName,
+					VendorPN:    row.VendorPartnumber,
+					Description: description,
+					Quantity:    lotQty,
+					BOMTotal:    bomTotal,
+					Estimate:    computeSingleLotTotal(priceMap, mapping.LotName, lotQty, func(p pricingLevels) *float64 { return p.Estimate }),
+					Stock:       computeSingleLotTotal(priceMap, mapping.LotName, lotQty, func(p pricingLevels) *float64 { return p.Stock }),
+					Competitor:  computeSingleLotTotal(priceMap, mapping.LotName, lotQty, func(p pricingLevels) *float64 { return p.Competitor }),
+				})
 			}
-			block.Rows = append(block.Rows, pricingRow)
 		}
 
 		for _, item := range cfg.Items {
@@ -696,6 +716,14 @@ func computeMappingTotal(priceMap map[string]pricingLevels, mappings []localdb.V
 	return floatPtr(total)
 }
 
+func computeSingleLotTotal(priceMap map[string]pricingLevels, lotName string, qty int, selector func(pricingLevels) *float64) *float64 {
+	price := selector(priceMap[lotName])
+	if price == nil || *price <= 0 {
+		return nil
+	}
+	return floatPtr(*price * float64(qty))
+}
+
 func totalForUnitPrice(unitPrice *float64, quantity int) *float64 {
 	if unitPrice == nil || *unitPrice <= 0 {
 		return nil
@@ -789,16 +817,6 @@ func pricingConfigSummaryRow(cfg ProjectPricingExportConfig, opts ProjectPricing
 	return record
 }
 
-func formatLotDisplay(mappings []localdb.VendorSpecLotMapping) string {
-	switch len(mappings) {
-	case 0:
-		return "н/д"
-	case 1:
-		return mappings[0].LotName
-	default:
-		return fmt.Sprintf("%s +%d", mappings[0].LotName, len(mappings)-1)
-	}
-}
 
 func formatMoneyValue(value *float64) string {
 	if value == nil {