Parse retention duration

A log platform stores each stream's retention as a compact duration string. A policy is one or more parts run together with nothing between them. Each part is one or more decimal digits followed by exactly one unit letter: d for days, h for hours, m for minutes, s for seconds. Units must appear in strictly descending size, d before h before m before s, so a unit shows up at most once and "30m2h" is refused. A day is 86400 seconds, an hour is 3600 and a minute is 60. Add the parts up. Anything outside that shape reports -1: an empty policy, digits with no unit after them, a unit with no digits before it, an uppercase letter, a space, a repeated unit, units out of order. Leading zeros are fine and no number runs past six digits. Return one integer per policy, in the order given.