Structured prefill for the “re-upload corrected version” flow.
Returns just the fields the new-document form needs to seed itself
so the frontend doesn’t have to fetch the entire job + canonical
extraction blob (which can be MiBs) just to read four strings.
Soft-deleted source jobs are still readable here — operators may
want to re-upload the corrected version of a job they’ve already
deleted.
The user-visible upload filename is not persisted on
document_artifacts today (only the synthetic storage-key tail
like original.pdf), so the response intentionally omits a
filename field rather than returning a misleading value. Re-add
when the artifact row carries the real filename.