Unfortunately, no one will be able to provide you with a conclusive assessment by examining the frame over the internet.
You can try asking LightCarbon - my guess is that they'll attempt to explain away the issue as a purely cosmetic defect and claim that the headtube area is sufficiently strong even with this blemish present. Which may be true, they know their carbon layup and molding process best. Or they may ignore your concerns, reasoning that they have your money and that you're somewhere far away. At the same time, it doesn't cost you anything to ask them, I'd start there.
Bringing the frame to a carbon expert may offer you peace of mind but now your low-cost frame isn't so low cost anymore. (Some will argue that paying for a carbon inspection should be weighed against the potential cost of dental surgery.)