feat(layout): MVSETUP sets a drawing up for plotting

In model space MVSETUP draws the sheet border at the drawing scale
(scale factor, paper width and height) and zooms to it, or switches to
a layout. On a layout it creates viewports in a bounding area (a single
one, a 2x2 engineering set of top/front/right/isometric views, or an
array with spacing), deletes picked objects, and scales picked
viewports to a paper/model unit ratio.

A viewport's fit to the model now measures the model along the
viewport's own view direction, so side and isometric views frame it
too.

Refs #1501

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

src/app/command_driver/mod.rs

@@ -882,6 +882,13 @@ impl OpenCADStudio {
             CmdResult::ZoomToWindow { p1, p2 } => {
                 self.handle_zoom_to_window(p1, p2);
             }
+            CmdResult::CommitAndZoom { entity, p1, p2 } => {
+                self.handle_commit_entities_and_exit(vec![entity], false, false);
+                self.handle_zoom_to_window(p1, p2);
+            }
+            CmdResult::ScaleViewports { handles, factor } => {
+                self.handle_scale_viewports(handles, factor);
+            }
             CmdResult::TwistView(twist) => {
                 self.handle_twist_view(twist);
             }