Add oven batch cost to AI Quick Quote (1 batch, DefaultOvenCycleMinutes or 50 min)

Previously the quick quote omitted the oven charge entirely, so saved quotes
were under-priced relative to full quotes from the same items.

Pricing: CalculatePricing now calculates ovenBatchCost = (cycleMin/60) × OvenOperatingCostPerHour
using DefaultOvenCycleMinutes (fallback 50 min), then adds it to the total as a quote-level
charge matching how PricingCalculationService handles oven costs.

Save path: SaveQuickQuoteRequest gains OvenBatchCost + OvenCycleMinutes; the Quote record
now stores OvenBatchCost, OvenCycleMinutes, and Total = ItemsSubtotal + OvenBatchCost.

Display: results card shows a sub-line under the estimate price:
"incl. oven 1 batch 50 min: $12.00"

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

src/PowderCoating.Application/DTOs/AI/AiQuickQuoteDtos.cs

@@ -65,6 +65,8 @@ public class SaveQuickQuoteRequest
     public decimal EstimatedUnitPrice { get; set; }
     public decimal MaterialCost { get; set; }
     public decimal LaborCost { get; set; }
+    public decimal OvenBatchCost { get; set; }
+    public int OvenCycleMinutes { get; set; }
 }
 
 /// <summary>Internal JSON schema returned by Claude for quick quote analysis.</summary>