SAN DIEGO — Federal agents in San Diego detained 72 people who had been in panga boats headed north into the U.S. earlier this week, Customs and Border Protection officials said. Agents with the Air and Marine Operations team spotted the three boats with their lights off late Monday, the agency said in a news release. The boats happened to be traveling at the same time but the three vessels were miles from each other and were not operating as a convoy, an agency spokesperson said. About 2 a.m., agents stopped two of the boats at sea. The third made it to shore in the area of Sunset Cliffs, and…