Splits failures into FatalError (abort the run) and JobError (record and
continue the batch), which is the distinction the batch runner needs.
DiskFull and SchemaTooNew are fatal on purpose: continuing past ENOSPC
only produces more corrupt artifacts.
Only NetworkError is retryable; retrying a private video is noise.
Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
