Add TCPA-compliant SMS consent tracking for prospect quotes

- Quote entity: ProspectSmsConsent (bool) + ProspectSmsConsentedAt (DateTime?) fields
- QuoteDtos: consent fields on Create/Update/Convert DTOs with TCPA guidance text
- Quote Create/Edit views: SMS consent checkbox shown when mobile number is entered
- Quote ConvertToCustomer view: staff must re-confirm consent carries over to customer record
- QuoteApproval: consent state exposed in ViewModel and ApprovalPage for transparency
- Consent timestamp cleared when prospect quote is linked to an existing customer
- Migration: AddProspectSmsConsent

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

src/PowderCoating.Web/Controllers/QuoteApprovalController.cs

@@ -454,6 +454,10 @@ public class QuoteApprovalController : Controller
             CustomerEmail = quote.Customer?.Email ?? quote.ProspectEmail,
             ExpirationDate = quote.ExpirationDate,
             ApprovalTokenExpiresAt = quote.ApprovalTokenExpiresAt,
+            ItemsSubtotal = quote.ItemsSubtotal,
+            OvenBatchCost = quote.OvenBatchCost,
+            ShopSuppliesAmount = quote.ShopSuppliesAmount,
+            ShopSuppliesPercent = quote.ShopSuppliesPercent,
             SubTotal = quote.SubTotal,
             DiscountAmount = quote.DiscountAmount,
             HideDiscountFromCustomer = quote.HideDiscountFromCustomer,