Angular dimension drawing: ray-based three-point frame, text beside the arc

Three-point angular dimensions take their sweep from the two rays and the
arc point (extension lines follow their own rays, straight and reflex
angles draw), dynamic angular dimensions store no text point so DIMTAD
places the text beside an unbroken arc, and dynamic dimensions carry a
DIMGAP override of a quarter text height.

Co-Authored-By: Claude Fable 5.1 <noreply@anthropic.com>

src/app/command_driver.rs

@@ -1838,7 +1838,7 @@ impl OpenCADStudio {
                         entity.common_mut().color = acadrust::types::Color::ByLayer;
                         // The dynamic form's screen-size and horizontal-text
                         // overrides go; the style draws it.
-                        for code in [dov::DIMSCALE, dov::DIMTIH, dov::DIMTOH] {
+                        for code in [dov::DIMSCALE, dov::DIMGAP, dov::DIMTIH, dov::DIMTOH] {
                             dov::set_on_entity(&mut entity, code, None);
                         }
                     } else {