scrap: fill the transform field in the Wayland display test helper

hbb_common main carries `WaylandDisplayInfo::transform` since 3d18e61, which
the webrtc branch's submodule is rebased on, but the rustdesk side of that
change is still open in #15889. Until it lands the scrap lib test no longer
builds; 0 is the field's own no-rotation default.

Co-Authored-By: Claude Fable 5.1 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_014W5DMsAHVBQ3tXV6pqkffD

libs/scrap/src/wayland/display.rs

@@ -519,6 +519,7 @@ mod tests {
             height,
             logical_size,
             refresh_rate: 60,
+            transform: 0,
         }
     }