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/Views/Quotes/ConvertToCustomer.cshtml

@@ -207,6 +207,47 @@
                     </div>
                 </div>
 
+                <!-- SMS Notifications -->
+                <div class="card mb-4 border-info">
+                    <div class="card-header bg-info bg-opacity-10">
+                        <h5 class="mb-0">
+                            <i class="bi bi-phone me-2"></i>SMS Notifications
+                        </h5>
+                    </div>
+                    <div class="card-body">
+                        <input type="hidden" asp-for="ProspectSmsConsentedAt" />
+                        @if (Model.SmsConsent)
+                        {
+                            <div class="alert alert-success alert-permanent mb-3 py-2">
+                                <i class="bi bi-check-circle me-1"></i>
+                                <strong>SMS consent was recorded on the quote</strong>
+                                @if (Model.ProspectSmsConsentedAt.HasValue)
+                                {
+                                    <span>on @Model.ProspectSmsConsentedAt.Value.ToLocalTime().ToString("MM/dd/yyyy")</span>
+                                }
+                            </div>
+                        }
+                        else
+                        {
+                            <div class="alert alert-warning alert-permanent mb-3 py-2">
+                                <i class="bi bi-exclamation-triangle me-1"></i>
+                                <strong>No SMS consent was recorded on the quote.</strong>
+                            </div>
+                        }
+                        <div class="form-check">
+                            <input asp-for="SmsConsent" class="form-check-input" id="SmsConsent" />
+                            <label class="form-check-label fw-semibold" for="SmsConsent">
+                                Customer has given verbal consent to receive SMS notifications
+                            </label>
+                        </div>
+                        <small class="text-muted d-block mt-1">
+                            <i class="bi bi-shield-check me-1"></i>
+                            Only check if the customer has explicitly agreed to receive text messages (TCPA compliance).
+                            If checked, the new customer record will have SMS enabled and a confirmation text will be sent.
+                        </small>
+                    </div>
+                </div>
+
                 <!-- Form Actions -->
                 <div class="mb-4">
                     <button type="submit" class="btn btn-success btn-lg">