The Freedom Tower, America’s top terror target, doesn’t have a single working surveillance camera inside — a stunning security lapse that let a New Jersey teen roam the top floors undetected. The video system for 1 World Trade Center “won’t be operational until the building opens later this year,” said a source familiar with the security plan. That means there is no footage of Justin Casquejo, 16, as he slipped by a sleeping guard to the antenna of the 1,776-foot-tall building.