Holed up in a cold, poky apartment in the faded Spanish coastal town of Gijón, fashion student Leo and her single mother Maria are living way beyond their means, but don’t tell them that: They’d prefer to think of it as their means simply not having caught up with them. There’s a fine, even invisible, line between dignity and denial in “El Planeta,” a fine-grained portrait of everyday poverty amid the lingering wreckage of the global financial crisis.