feat(field): FIELDDISPLAY gray field background (screen only, profile setting)

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

src/app/commands/mod.rs

@@ -668,6 +668,7 @@ inventory::submit!(crate::command::CommandRegistration {
         "DGNFRAME",
         "PDFOSNAP",
         "UOSNAP",
+        "FIELDDISPLAY",
         "PDFIMPORTMODE",
         "PDFIMPORTFILTER",
         "PDFIMPORTLAYERS",

src/app/commands/styleprops.rs

@@ -1025,6 +1025,7 @@ impl OpenCADStudio {
                     | "DWFOSNAP"
                     | "DGNOSNAP"
                     | "UOSNAP"
+                    | "FIELDDISPLAY"
                     | "PDFIMPORTMODE"
                     | "PDFIMPORTFILTER"
                     | "PDFIMPORTLAYERS"
@@ -1232,6 +1233,40 @@ impl OpenCADStudio {
                         }
                         return Some(self.finish_dispatch(cmd));
                     }
+                    if name == "FIELDDISPLAY" {
+                        let current = i16::from(crate::entities::field::display());
+                        match value.as_deref().map(|v| v.trim().parse::<i16>().ok().filter(|v| (0..=1).contains(v))) {
+                            Some(Some(mode)) => {
+                                if current != mode {
+                                    crate::entities::field::set_display(mode == 1);
+                                    // A profile setting: redraw the fields of every open drawing.
+                                    for tab in &mut self.tabs {
+                                        let changes: Vec<_> = tab
+                                            .scene
+                                            .document
+                                            .entities()
+                                            .filter(|e| crate::entities::field::hosts_field(&tab.scene.document, e))
+                                            .map(|e| (e.common().handle, crate::scene::ChangeKind::Modified))
+                                            .collect();
+                                        if !changes.is_empty() {
+                                            tab.scene.bump_entities(&changes);
+                                        }
+                                    }
+                                    self.save_config();
+                                }
+                            }
+                            Some(None) => {
+                                self.command_line.push_error(crate::t!("Requires 0 or 1 only.").as_ref());
+                                self.command_line.push_output(&format!("Enter new value for FIELDDISPLAY <{current}>:"));
+                                self.pending_setvar = Some(name.clone());
+                            }
+                            None => {
+                                self.command_line.push_output(&format!("Enter new value for FIELDDISPLAY <{current}>:"));
+                                self.pending_setvar = Some(name.clone());
+                            }
+                        }
+                        return Some(self.finish_dispatch(cmd));
+                    }
                     if matches!(name.as_str(), "PDFOSNAP" | "DWFOSNAP" | "DGNOSNAP" | "UOSNAP") {
                         use crate::scene::model::pdf_vector as pv;
                         use codec::entities::UnderlayType;