Job Result

Fetch result.json (409 until state is ``done``, 410 once the results are purged or past their retention TTL). The 410 is authoritative at read time: an expired job answers Gone even if the retention sweeper has not deleted its files yet. ``?timings=true`` folds the job's per-page render/OCR timings (from the span log) into the response under ``page_timings``. Off by default, so the common fetch streams the lean result file straight from disk.