Executes a single YouTube import/trim job end to end: downloads the full
source video, trims the requested range with a local ffmpeg pass, uploads
the result to R2, and hands off to the standard upload/distribution
pipeline. Updates the job's status/progress as it proceeds so callers
polling getYoutubeImportJobById see live progress.
Parameters
jobId: string
YoutubeImportJob id to execute. Must already exist with
status pending or downloading (after atomic claim).
Executes a single YouTube import/trim job end to end: downloads the full source video, trims the requested range with a local ffmpeg pass, uploads the result to R2, and hands off to the standard upload/distribution pipeline. Updates the job's status/progress as it proceeds so callers polling
getYoutubeImportJobByIdsee live progress.