_generate_single_video was a ~250-line copy of the batch helpers
(_prepare_generation_work_item / _run_forward_batch /
_postprocess_generation_output); it now delegates to them, so save/mux
fixes land once. prompt_embeds passthrough moves into
_prepare_generation_work_item. The per-request pipeline-override block
(three copies) is factored into _resolve_request_fastvideo_args.
Only intentional non-output-affecting delta: the single path no longer
overlaps the pinned staging-buffer allocation with the forward thread
(the shared helper allocates after join, as the batch path already did).
No behavior change; batching-touched suite 140 passed before and after.
SolitaryThinker
7592b57ec0