From James Harden’s extension to addressing “toughness” issues, Daryl Morey and the Sixers’ front office have a lot of work ahead of them. Things were sunny in Philadelphia after a Game 4 win over the Heat. James Harden turned back the clock with an electric 16-point fourth quarter. Budding star Tyrese Maxey was finding his footing. Danny Green’s shooting variance had evened out in a big way. Most importantly, Joel Embiid returned to the lineup — albeit with a broken face and wonky thumb — to help propel both wins at the Wells Fargo Center. The series was tied 2-2,…