PHILADELPHIA — The next franchise cornerstone quickly took his seat. Jalen Carter swiped sweat from his brow as he sat in a media tent that included members of his family. His post-practice shower was doing very little to slow down the blood still vaulting through his veins. His body remained energized by the start of the first of six more scheduled seasons with the Philadelphia Eagles, who signed Carter to a four-year, $152 million extension.Carter started thanking everyone at a mile a minute. “Let me slow down,” he said. He thanked God. His coaches. His teammates. He looked up and saw Jordan Davis standing in the back. They’d played at Georgia together. They’d come up on rookie contracts together. They’d now attended each other’s post-contract extension press conferences. Carter had sat in the back of the auditorium in March when Davis discussed his three-year, $78 million contract.“It’s just a blessing to see him, to work with him a couple more years,” Carter said. “I’m just happy I can be here and play with the guys I grew up with.”The Eagles could not be more pleased with this picture. This is the image the organization sees when it looks in the mirror, the one it wants to project to the world as a well-proven culture. General manager Howie Roseman supplied its definition earlier Wednesday morning: “If I do well, I’m gonna get rewarded. I don’t have to go somewhere else to do that.” Carter could confirm the three-step model — as could Davis, and Cam Jurgens, and Landon Dickerson and DeVonta Smith.