PDF underlays: attach prompts and definitions, display adjustments and clipping, Properties, snapping, PDFCLIP and PDFIMPORT

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

src/app/commands/display.rs

@@ -1861,8 +1861,7 @@ impl OpenCADStudio {
                 }
             }
 
-            "POINTCLOUDATTACH" | "RECAP" | "SYNCPVIEWPORTS" | "UNDERLAYLAYERS"
-            | "UOSNAP" => {
+            "POINTCLOUDATTACH" | "RECAP" | "SYNCPVIEWPORTS" | "UNDERLAYLAYERS" => {
                 self.command_line
                     .push_info(crate::tf!("{cmd}: not yet implemented.").as_ref());
             }