SAN FRANCISCO – Everything the Warriors imagined when they pinpointed Al Horford as a main offseason target in NBA free agency came together in a Christmas culmination for the 39-year-old who missed the previous seven games over the last three weeks.The ability to stretch the floor as a center who’s a legitimate 3-point threat came back to life immediately upon Horford’s return in a 126-116 win against the Dallas Mavericks at Chase Center. So did his basketball smarts in Year 19, his rebounding, being a difference maker defensively and imprinting his impact in multiple ways. This was what made the Warriors sink even further into trusting experience instead of Father Time’s worries.Horford, in only 11 minutes off the benc,h scored a season-high 14 points and had four rebounds, two assists and two steals. His coaches and teammates after the win spoke to what a healthy Horford does for them.“It’s the vision of what he would add to our team from the jump,” Steph Curry said. “I know that he’s battled a lot of injuries and absences and he’s trying to, personally, I’m sure, find a rhythm. That availability is...