One test loses the lock while toast.mp4, the last original, downloads:
quak backup must then write no file's JSON and no album. Another takes the
lock with lockBackupDirectory, passes it to lib.backup() as lock, and loses
it: the backup must reject, and the lock's lost must hold the reason. The
fake server now holds whichever download a test names. Both fail until the
backup checks its lock before each file and takes the caller's lock itself.
Model: opus-5-5
sneak
dc1f483a3d