Clara didn’t die. Three things give it away. First, when the guy met the Raven at the beginning one of the aliens said “don’t run… They always run.” Clara didn’t run. That’s going to mean something. Second, the teleporter dropped when the Doctor was zapped out to wherever he is. That’s how Clara saves him. Third, there was a medical pod/stasis chamber where they kept someone else who was “dead”. I’ve no doubt Clara is leaving because Jenna Coleman wants to do other things (can’t blame her). But I still think there’s going to be a happy ending. If only because every other companion since the relaunch has got a happy (or at least bittersweet) ending.