The defense business of iRobot has been formally purchased by Arlington Capital Partners, marking the company's debut as a stand-alone, privately held robotics business. The unit will now be known as Endeavor Robotics and will be led by Sean Bielat, a former iRobot employee who also serves in the Marine Corps Reserve and has twice run for Congress. In February, iRobot, seeking to focus on its home robot business, agreed to sell its defense and security business -- with 2015...