Add Custom Powder Order line item and fix CSV import FinalPrice crash

Custom powder/incoming powder material cost now flows into a separate
auto-generated 'Custom Powder Order' line item instead of rolling into
individual item prices, so users can add shipping charges before the
customer sees the total. A dashed yellow preview card in the wizard
shows the material cost and lets users edit the total (including shipping)
before saving. After first save the price is user-owned.

Also fixes a fatal CSV import crash when FinalPrice contains a non-numeric
value (e.g. 'false' from a spreadsheet formula): the job CSV importer now
streams rows one at a time with a lenient decimal converter, treating bad
values as $0 with a per-row warning instead of aborting the entire import.

Updated HelpKnowledgeBase.cs and Help articles (Jobs, Quotes) with
Custom Powder Order behavior and a new Data Import / Export section.

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

src/PowderCoating.Application/Services/QuotePricingAssemblyService.cs

@@ -90,8 +90,9 @@ public class QuotePricingAssemblyService : IQuotePricingAssemblyService
     {
         ArgumentNullException.ThrowIfNull(itemDtos);
 
+        var dtoList = itemDtos.ToList();
         var items = new List<QuoteItem>();
-        foreach (var itemDto in itemDtos)
+        foreach (var itemDto in dtoList)
         {
             var item = BuildQuoteItem(itemDto, quoteId, companyId, createdAtUtc);
             await ApplyPricingAsync(item, itemDto, companyId, ovenRateOverride);
@@ -102,6 +103,17 @@ public class QuotePricingAssemblyService : IQuotePricingAssemblyService
             items.Add(item);
         }
 
+        // Option B: auto-create the Custom Powder Order item only on first save.
+        // Once user-owned, they manage its price (e.g. to add shipping) — we never overwrite it.
+        bool hasExistingCustomPowderOrder = dtoList.Any(d =>
+            d.IsGenericItem && d.Description?.StartsWith("Custom Powder Order") == true);
+        if (!hasExistingCustomPowderOrder)
+        {
+            var customPowderItem = await BuildCustomPowderOrderItemAsync(dtoList, quoteId, companyId, createdAtUtc);
+            if (customPowderItem != null)
+                items.Add(customPowderItem);
+        }
+
         return items;
     }
 
@@ -461,4 +473,78 @@ public class QuotePricingAssemblyService : IQuotePricingAssemblyService
             return null;
         }
     }
+
+    /// <summary>
+    /// Scans all coat DTOs for powder that must be ordered (custom or incoming) and returns a
+    /// single "Custom Powder Order" QuoteItem aggregating all material costs and color names.
+    /// Returns null when no such coats are found. Used by <see cref="CreateQuoteItemsAsync"/>
+    /// on the first save only — Option B means the user owns the price after creation.
+    ///
+    /// Two coat types qualify:
+    ///   - Custom powder: no InventoryItemId, manual PowderCostPerLb &gt; 0
+    ///   - Incoming powder: InventoryItemId set but inventoryItem.IsIncoming == true
+    ///     (auto-created by <see cref="CreateIncomingInventoryItemAsync"/>; PowderCostPerLb cleared
+    ///      after creation, so cost comes from inventoryItem.UnitCost instead)
+    /// </summary>
+    private async Task<QuoteItem?> BuildCustomPowderOrderItemAsync(
+        IReadOnlyList<CreateQuoteItemDto> itemDtos, int quoteId, int companyId, DateTime createdAtUtc)
+    {
+        var colorNames = new List<string>();
+        decimal totalCost = 0m;
+
+        foreach (var itemDto in itemDtos)
+        {
+            if (itemDto.Coats == null) continue;
+            foreach (var coat in itemDto.Coats)
+            {
+                if (!coat.InventoryItemId.HasValue &&
+                    coat.PowderToOrder.HasValue && coat.PowderToOrder.Value > 0 &&
+                    coat.PowderCostPerLb.HasValue && coat.PowderCostPerLb.Value > 0)
+                {
+                    // Custom powder: no inventory link, user entered cost per lb manually
+                    totalCost += coat.PowderToOrder.Value * coat.PowderCostPerLb.Value;
+                    if (!string.IsNullOrWhiteSpace(coat.ColorName))
+                        colorNames.Add(coat.ColorName);
+                }
+                else if (coat.InventoryItemId.HasValue && coat.PowderToOrder.HasValue && coat.PowderToOrder.Value > 0)
+                {
+                    // Incoming powder: catalog-selected; CreateIncomingInventoryItemAsync set InventoryItemId
+                    // and cleared PowderCostPerLb, so cost must come from the inventory item's UnitCost
+                    var invItem = await _unitOfWork.InventoryItems.GetByIdAsync(coat.InventoryItemId.Value);
+                    if (invItem?.IsIncoming == true)
+                    {
+                        totalCost += coat.PowderToOrder.Value * invItem.UnitCost;
+                        var colorName = !string.IsNullOrWhiteSpace(coat.ColorName) ? coat.ColorName : invItem.Name;
+                        if (!string.IsNullOrWhiteSpace(colorName))
+                            colorNames.Add(colorName);
+                    }
+                }
+            }
+        }
+
+        if (totalCost <= 0) return null;
+
+        var uniqueColors = colorNames
+            .Distinct(StringComparer.OrdinalIgnoreCase)
+            .ToList();
+        var description = uniqueColors.Any()
+            ? $"Custom Powder Order ({string.Join(", ", uniqueColors)})"
+            : "Custom Powder Order";
+
+        return new QuoteItem
+        {
+            QuoteId = quoteId,
+            Description = description,
+            Quantity = 1,
+            IsGenericItem = true,
+            ManualUnitPrice = totalCost,
+            UnitPrice = totalCost,
+            TotalPrice = totalCost,
+            ItemMaterialCost = totalCost,
+            CompanyId = companyId,
+            CreatedAt = createdAtUtc,
+            Coats = [],
+            PrepServices = []
+        };
+    }
 }