Point clouds: drawn from their scans, placed, cropped and attached as the reference does

Scans (.rcs) and projects (.rcp) are read and their points drawn as
screen-sized dots, coloured by the cloud's stylization. The cloud's
placement carries its scale and rotation; its extents and crops stay in
the scan's coordinates. A missing scan shows the extents with the saved
path. -POINTCLOUDATTACH / POINTCLOUDATTACH, POINTCLOUDCROP and the
POINTCLOUD* settings follow the reference's prompts and messages, the
Properties list is the reference's, and a locked cloud is left alone by
edits.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

src/app/commands/display.rs

@@ -1911,7 +1911,7 @@ impl OpenCADStudio {
             }
 
             "UNDERLAYLAYERS" | "ULAYERS" => self.open_underlay_layers_dialog(i),
-            "POINTCLOUDATTACH" | "RECAP" | "SYNCPVIEWPORTS" => {
+            "RECAP" | "SYNCPVIEWPORTS" => {
                 self.command_line
                     .push_info(crate::tf!("{cmd}: not yet implemented.").as_ref());
             }