Restore IncludePrepCost pricing for catalog items with abnormal prep

The flag should default off (catalog DefaultPrice used as-is) but remain
functional so users can opt in when a job needs exceptional prep time
(e.g. 120-min outgassing vs. the typical 30 min baked into the catalog price).

Previous commit removed this entirely — restoring with correct default behavior.

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

src/PowderCoating.Application/Services/PricingCalculationService.cs

@@ -391,8 +391,17 @@ public class PricingCalculationService : IPricingCalculationService
             baseSubtotal = baseUnitPrice * item.Quantity;
             _logger.LogInformation("Catalog base: ${Price} × {Qty} = ${Base}", baseUnitPrice, item.Quantity, baseSubtotal);
 
-            // Catalog DefaultPrice is always the base — prep service labor is never added on top.
-            // PrepServices on catalog items are used for scheduling only, not pricing.
+            // Optionally add prep service labor for catalog items when the job requires abnormal
+            // prep time (e.g. 120-min outgassing on a part that normally takes 30). The flag
+            // defaults to false so the DefaultPrice is used as-is for typical jobs.
+            if (!item.IsAiItem && item.IncludePrepCost && item.PrepServices != null && item.PrepServices.Any())
+            {
+                var totalPrepMinutes = item.PrepServices.Sum(ps => ps.EstimatedMinutes);
+                var prepLaborCost = (totalPrepMinutes / 60m) * costs.StandardLaborRate;
+                baseSubtotal += prepLaborCost;
+                totalLaborCost += prepLaborCost;
+                _logger.LogInformation("Catalog item extra prep: {Min} min × ${Rate}/hr = ${Cost}", totalPrepMinutes, costs.StandardLaborRate, prepLaborCost);
+            }
 
             // Custom (non-inventory) powder coats must be purchased separately — add their material
             // cost on top of the catalog base price. Inventory powder is assumed baked into DefaultPrice.