The SPA needs the item's row id to call
GET /api/playouts/items/{id}/scheduling-context. Plumbed through
PlayoutItemViewModel -> PlayoutItemResponseModel as a nullable Id
(null for synthesized UNSCHEDULED gap rows, which are PlayoutGaps,
not PlayoutItems). Additive for existing consumers (Playouts.razor
reads the VM by property). Regenerated v1.json + v1.d.ts.
Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>