Read one product video plan run.

Where one plan run is (queued → planning → ready, or failed — a run left behind by an interrupted worker reads failed with a plain sentence to ask again), the request it runs, and once ready its trailerJobId, reviewUrl, the conversation bound to the draft, nextStep: approve_trailer_plan and its live plan check (coverage, which follows later beat edits). Another account's or project's run is 404 product_video_plan_not_found. Planning a product video turns one feature of the project's feature map, or a named release and its features, and the project's recorded captures into an ordinary draft trailer — each beat names its capture, the stretch of it it plays, a narrated line, whether the beat keeps its own sound, and its depth — and it is free: it answers at once, the run is polled until it is ready, and the result is an ordinary capture-only draft trailer approved with approve_trailer_plan. A read: it never plans, renders or edits. Scope: story:read.