From left, Allie Lloyd, Alyson Viche and Kairi McWhorter play on a tire swing outside the Chilkat Valley Preschool building under construction on First Avenue South. The building, attached to the Haines Senior Center, is to be substantially complete by Aug. 1. School is scheduled to start in early September. A building dedication will be held in mid-August, said project advocate Renee Hoffman. Improvements to the grounds and landscaping likely will wait until next spring,…