Regenerate selected passages as a new dub

Create a new asynchronous job using saved edits for 1–50 selected passages and the existing rendered audio for all other passages. The previous job is unchanged. If only a passage's source text changed, its translation is refreshed. A supplied pronunciation_text is the full spoken passage and does not appear in subtitles. Reuse the same Idempotency-Key and body after a lost response. A completed revision counts only the source time covered by selected passages, with overlapping time counted once. Exports carry no additional usage.