Swap in the Riverdi RVT70 panel, flip the rotation, and stop ^C orphaning harness runs

internal/drm/drm.go

@@ -133,7 +133,7 @@ func Unpack(v uint32) (r, g, b uint8) {
 }
 
 // Offset maps the portrait canvas onto the landscape panel, a quarter turn that
-// puts logical top on the panel's right edge.
-func Offset(x, y, stride, panelW int) int {
-	return x*stride + (panelW-1-y)*4
+// puts logical top on the panel's left edge.
+func Offset(x, y, stride, panelH int) int {
+	return (panelH-1-x)*stride + y*4
 }