Aparna Bhardwaj’s 15-year-old son, Nikash, and his best friend wanted to camp out all night in front of the new Shake Shack in Palo Alto before its opening. They wanted to be first in line. But it’s finals week, so the devoted mother made a deal with the boys. She would leave their house just 5 minutes away in Menlo Park at 6 a.m., she said, and save them a place at the front of the line — as long as they promised to study for their math final on Monday. Done, the boys said.