Browser and viewport: item menu, per-item eyes, Delete key with confirmation

Right-click on any browser item (body, surface, datum, partition, set,
material, section, step, boundary condition, load, reference point,
coupling, contact, fluid domain) opens its menu: Edit…, Hide/Show,
Isolate, Show All, Active in step (boundary conditions and loads) and
Delete…. A right click on a datum or a partition's cut face in the
viewport opens the same menu. Each item the viewport draws on its own
has an eye; hidden items are neither drawn nor picked. Datums and
partitions are selectable with properties. Delete… and the Delete key
ask first (the prompt lists what uses the item: a datum's partitions
are deleted with it, other definitions in use are refused); ui.prompt
answers it. Every entry runs the same command as the ribbon and forms.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01UhhZMBTviDQxZvwnyP89fo

crates/ui-egui/src/context.rs

@@ -253,16 +253,19 @@ fn properties(app: &mut ModelApp, ui: &mut egui::Ui, t: &Tokens, kind: Def, name
     });
     ui.add_space(6.0);
     let (mut edit, mut delete) = (false, false);
+    let editing = kind.edit_command(&app.session.model, name);
     ui.horizontal(|ui| {
-        edit = ui.button("Edit…").on_hover_text(kind.command("edit")).clicked();
-        delete = ui.button("Delete").on_hover_text(kind.command("delete")).clicked();
+        if let Some(command) = &editing {
+            edit = ui.button("Edit…").on_hover_text(command).clicked();
+        }
+        delete = ui.button("Delete…").on_hover_text(format!("{} (Delete key)", kind.command("delete"))).clicked();
     });
     if deselect {
         app.selected = None;
-    } else if edit && let Some(v) = browser::definition(&app.session.model, kind, name) {
-        app.open_form(&kind.command("edit"), v);
-    } else if delete && app.run(&kind.command("delete"), json!({"name": name})).is_ok() {
-        app.selected = None;
+    } else if edit && let Some((command, params)) = kind.edit(&app.session.model, name) {
+        app.open_form(&command, params);
+    } else if delete {
+        app.ask_delete(kind, name);
     }
 }