NEW YORK (AP) — As a citizen of both France and America, Margaux Lantelme has noticed a difference in how store cashiers work in the two countries: in France, they do their jobs sitting down. In the U.S., where Lantelme works a register at REI , cashiers typically spend eight hours a day on their feet. For Lantelme, a former kayaking instructor, prolonged standing can trigger flare-ups of chronic pain that limit her mobility. She requested a chair to use during her shift and got one. But after