The Las Vegas Raiders officially signed rookie Jackson Powers-Johnson to his four-year deal, the team announced in a release on Monday. Powers-Johnson inked for four years, $8.767 million on a deal that’s fully guaranteed. His signing bonus is an estimated $3.196 million. He was the last of the team’s eight draftees to ink his rookie contract. The Raiders drafted the talented center with the No. 44 overall selection in the second round of the 2024 NFL Draft out of Oregon. After playing out his rookie deal, Powers-Johnson will either sign an extension with the Raiders or test the free agency ma…