The CCTV frame proxy marks a Street View fallback with X-CCTV-Source, but the portable source dropped the header and get_cctv_snapshot always reported a current view credited to the camera's agency. The source now keeps the recognised provenance, and the tool labels Street View frames as historical Google imagery, refuses synthetic placeholders, and reports unknown provenance without claiming a current view.
Add getFrame(camera) to the CCTV source. It reads one frame through the
registered frame endpoint the layer already uses and returns its content
type and bytes, so code outside the layer can show a camera's view.