fix(annoscale): make the OBJECTSCALE dialog reachable

The Annotation Object Scale dialog (advertised in v0.8.2) was dead code:
bare OBJECTSCALE was caught by the immediate "mark selection annotative"
arm, so the `"OBJECTSCALE" =>` dialog arm below it never ran and nothing
else opened the dialog. Move the quick mark to an explicit `OBJECTSCALE ADD`
keyword (what the ribbon "Add Scale" button now sends, dispatched whole so
it doesn't collide), leaving bare OBJECTSCALE to open the dialog.

src/modules/annotate/mod.rs

@@ -207,7 +207,11 @@ impl CadModule for AnnotateModule {
                             icon: crate::modules::IconKind::Svg(include_bytes!(
                                 "../../../assets/icons/add_scale.svg"
                             )),
-                            event: crate::modules::ModuleEvent::Command("OBJECTSCALE".to_string()),
+                            // The quick "mark annotative at the current scale"
+                            // action; bare OBJECTSCALE opens the manage dialog.
+                            event: crate::modules::ModuleEvent::Command(
+                                "OBJECTSCALE ADD".to_string(),
+                            ),
                         }),
                         RibbonItem::Tool(crate::modules::ToolDef {
                             id: "SCALELISTEDIT",