feat: redesign project pricing export — FOB/DDP basis, variant filename, article column

- Add FOB/DDP basis to export options; DDP multiplies all prices ×1.3
- Rename export file from "pricing" to "{FOB|DDP} {variant}" (e.g. "FOB v1")
- Fix server article missing from CSV summary row (PN вендора column)
- Skip per-row breakdown when neither LOT nor BOM is selected
- Remove empty separator rows between configurations
- Redesign export modal: split into Артикул / Цены / Базис поставки sections

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

internal/services/export.go

@@ -56,11 +56,24 @@ type ProjectExportData struct {
 }
 
 type ProjectPricingExportOptions struct {
-	IncludeLOT        bool `json:"include_lot"`
-	IncludeBOM        bool `json:"include_bom"`
-	IncludeEstimate   bool `json:"include_estimate"`
-	IncludeStock      bool `json:"include_stock"`
-	IncludeCompetitor bool `json:"include_competitor"`
+	IncludeLOT        bool    `json:"include_lot"`
+	IncludeBOM        bool    `json:"include_bom"`
+	IncludeEstimate   bool    `json:"include_estimate"`
+	IncludeStock      bool    `json:"include_stock"`
+	IncludeCompetitor bool    `json:"include_competitor"`
+	Basis             string  `json:"basis"`       // "fob" or "ddp"; empty defaults to "fob"
+	SaleMarkup        float64 `json:"sale_markup"` // DDP multiplier; 0 defaults to 1.3
+}
+
+func (o ProjectPricingExportOptions) saleMarkupFactor() float64 {
+	if o.SaleMarkup > 0 {
+		return o.SaleMarkup
+	}
+	return 1.3
+}
+
+func (o ProjectPricingExportOptions) isDDP() bool {
+	return strings.EqualFold(strings.TrimSpace(o.Basis), "ddp")
 }
 
 type ProjectPricingExportData struct {
@@ -251,18 +264,16 @@ func (s *ExportService) ToPricingCSV(w io.Writer, data *ProjectPricingExportData
 		return fmt.Errorf("failed to write pricing header: %w", err)
 	}
 
-	for idx, cfg := range data.Configs {
+	writeRows := opts.IncludeLOT || opts.IncludeBOM
+	for _, cfg := range data.Configs {
 		if err := csvWriter.Write(pricingConfigSummaryRow(cfg, opts)); err != nil {
 			return fmt.Errorf("failed to write config summary row: %w", err)
 		}
-		for _, row := range cfg.Rows {
-			if err := csvWriter.Write(pricingCSVRow(row, opts)); err != nil {
-				return fmt.Errorf("failed to write pricing row: %w", err)
-			}
-		}
-		if idx < len(data.Configs)-1 {
-			if err := csvWriter.Write([]string{}); err != nil {
-				return fmt.Errorf("failed to write separator row: %w", err)
+		if writeRows {
+			for _, row := range cfg.Rows {
+				if err := csvWriter.Write(pricingCSVRow(row, opts)); err != nil {
+					return fmt.Errorf("failed to write pricing row: %w", err)
+				}
 			}
 		}
 	}
@@ -424,6 +435,9 @@ func (s *ExportService) buildPricingExportBlock(cfg *models.Configuration, opts
 				Competitor:  totalForUnitPrice(priceMap[item.LotName].Competitor, item.Quantity),
 			})
 		}
+		if opts.isDDP() {
+			applyDDPMarkup(block.Rows, opts.saleMarkupFactor())
+		}
 		return block, nil
 	}
 
@@ -443,9 +457,29 @@ func (s *ExportService) buildPricingExportBlock(cfg *models.Configuration, opts
 		})
 	}
 
+	if opts.isDDP() {
+		applyDDPMarkup(block.Rows, opts.saleMarkupFactor())
+	}
+
 	return block, nil
 }
 
+func applyDDPMarkup(rows []ProjectPricingExportRow, factor float64) {
+	for i := range rows {
+		rows[i].Estimate = scaleFloatPtr(rows[i].Estimate, factor)
+		rows[i].Stock = scaleFloatPtr(rows[i].Stock, factor)
+		rows[i].Competitor = scaleFloatPtr(rows[i].Competitor, factor)
+	}
+}
+
+func scaleFloatPtr(v *float64, factor float64) *float64 {
+	if v == nil {
+		return nil
+	}
+	result := *v * factor
+	return &result
+}
+
 // resolveCategories returns lot_name → category map.
 // Primary source: pricelist items (lot_category). Fallback: local_components table.
 func (s *ExportService) resolveCategories(pricelistID *uint, lotNames []string) map[string]string {
@@ -735,7 +769,7 @@ func pricingConfigSummaryRow(cfg ProjectPricingExportConfig, opts ProjectPricing
 		record = append(record, "")
 	}
 	record = append(record,
-		"",
+		emptyDash(cfg.Article),
 		emptyDash(cfg.Name),
 		fmt.Sprintf("%d", exportPositiveInt(cfg.ServerCount, 1)),
 	)