fix(operations): preserve UTC markers in response timestamps

JobTrackerApi/Controllers/OperationsController.cs

@@ -60,16 +60,17 @@ public sealed record OperationDto(
     bool CanCancel,
     bool CanRetry)
 {
+    // SQLite drops DateTime.Kind; these fields retain their stored UTC ticks.
     public static OperationDto From(UserOperation operation) => new(
         operation.Id,
         operation.TaskType,
         operation.Status,
         operation.SubjectType,
-        operation.CreatedAtUtc,
-        operation.StartedAtUtc,
-        operation.CompletedAtUtc,
-        operation.DeadlineAtUtc,
-        operation.CancellationRequestedAtUtc,
+        DateTime.SpecifyKind(operation.CreatedAtUtc, DateTimeKind.Utc),
+        operation.StartedAtUtc is { } started ? DateTime.SpecifyKind(started, DateTimeKind.Utc) : null,
+        operation.CompletedAtUtc is { } completed ? DateTime.SpecifyKind(completed, DateTimeKind.Utc) : null,
+        operation.DeadlineAtUtc is { } deadline ? DateTime.SpecifyKind(deadline, DateTimeKind.Utc) : null,
+        operation.CancellationRequestedAtUtc is { } cancellation ? DateTime.SpecifyKind(cancellation, DateTimeKind.Utc) : null,
         operation.ProgressStage,
         operation.ProgressPercent,
         operation.FailureCategory,
@@ -116,8 +117,8 @@ public sealed class NotificationsController(UserNotificationStore notifications)
         notification.Title,
         notification.Message,
         notification.LinkPath,
-        notification.CreatedAtUtc,
-        notification.ReadAtUtc);
+        DateTime.SpecifyKind(notification.CreatedAtUtc, DateTimeKind.Utc),
+        notification.ReadAtUtc is { } read ? DateTime.SpecifyKind(read, DateTimeKind.Utc) : null);
 }
 
 public sealed record NotificationDto(