Preferences test: the recent items count is 20

The test checked only that the count was whole, so another default would
pass. It asserts 20, InDesign's default.

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

crates/ui-egui/src/dialogs.rs

@@ -7435,7 +7435,7 @@ mod tests {
         let labels = dialog_frame(&mut app, &ctx, screen, vec![]);
         visible_label(&labels, screen, "Number of Recent Items to Display:");
         let count = app.ui.dialog.as_ref().unwrap().n("recentFilesMax").unwrap();
-        assert_eq!(count.fract(), 0.0);
+        assert_eq!(count, 20.0, "InDesign's default");
         visible_label(&labels, screen, &format!("{count}"));
         assert!(!labels.iter().any(|(t, _, _)| t.trim() == format!("{count:.1}")), "no decimal shown");
     }