A Boston-area supermarket chain will pay $800,000 to settle allegations that it violated state labor laws by failing to pay workers overtime and premium weekend rates. The state attorney general’s office said Tuesday that C-Mart stores, which specialize in Asian foods, were issued 15 citations in 2021 following an investigation by the attorney general’s Fair Labor Division. The settlement was reached after C-Mart appealed the 2021 citations. The C-Mart locations were in the South End, Chinatown and Quincy. An attorney for the supermarket said the company cooperated with the investigation and is pleased to have reached an agreement.