requestRectangleChecksum
abstract fun requestRectangleChecksum(requestId: Int, page: Int, top: Int, left: Int, bottom: Int, right: Int)
Requests a VT420 rectangular-area checksum (DECRQCRA).
Coordinates retain DEC's one-based inclusive representation so core can apply the active origin-mode policy. page uses DEC's one-based page numbering; 0 denotes omission. The host/core response path owns page capability policy and emits no bytes for unsupported requests.