A contractor that provides security guards and related services to Apple Inc. is cutting more than 600 workers based at the iPhone maker's facilities statewide, including 87 in Elk Grove. Security Industry Specialists Inc. plans to let go of the workers April 28, Julia Prybyla, the company's director of human resources, said in a series of letters to California employment officials. It planned to notify affected workers Feb. 27, she said in the letters, which were dated Feb. 24. The Culver City...