Fix SMS Agreements history modal showing undefined values

System.Text.Json serializes PascalCase by default but the modal JS
expected camelCase — added CamelCase naming policy to the serializer.

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

src/PowderCoating.Web/Views/SmsAgreements/Index.cshtml

@@ -222,7 +222,7 @@
                                                         AgreedAt = a.AgreedAt.ToString("MMM d, yyyy 'at' h:mm tt") + " UTC",
                                                         IpAddress = a.IpAddress ?? "—",
                                                         UserAgent = a.UserAgent ?? "—"
-                                                    }))">
+                                                    }), new System.Text.Json.JsonSerializerOptions { PropertyNamingPolicy = System.Text.Json.JsonNamingPolicy.CamelCase })">
                                                 @row.AllAgreements.Count <i class="bi bi-clock-history ms-1"></i>
                                             </button>
                                         }