Get a download URL for the raw camera capture

Works with: Personal token

Returns a signed URL for the raw camera capture as MP4, merged from the source fragments rather than the rendered composite. This is the camera on its own, for clients that want to re-edit the recording themselves. If it has not been produced yet the merge is started and 202 is returned — poll until 200. A 409 means this recording has no camera stream. Raw assets are always the original recording's captures: an edit's `public_id` resolves to the recording it was cut from, the edit's cuts are not applied, and the response's `public_id` is the original's. For the edited video use `/download`. Requires a personal token, edit access to the recording, the `recording:download` workspace capability (or ownership of the recording), and the raw-asset download plan feature on the recording's workspace.