Leave no doubt to your imaginations, Jessie Diggins, in-form and yellow-bibbed as the World Cup leader, stamped her authority on the 2021 season with gusto in Falun, Sweden. She won the 10-kilometer individual skate on Friday in 23:35.9. This was Diggins’s eighth individual win on the World Cup — all have been in skate. With the sun hanging on the horizon and unable to warm the air above squeaky-snow-cold, this was a key opportunity to...