The Times’s Suzanne Daley reports on struggling Spanish workers who have avoided losing their jobs but often face weeks or months without paychecks. VALENCIA, Spain — Over the past two years, Ana María Molina Cuevas, 36, has worked five shifts a week in a ceramics factory on the outskirts of this city, hand-rolling paint onto tiles. But at the end of the month, she often went unpaid. Still, she ke