fix(props): angle rows format via AUNITS, not LUNITS (#297)

Every angle row went through the linear formatter, so switching LUNITS
to Architectural showed a block's Rotation as feet-and-inches — and the
string wouldn't parse back, wedging the field until it was cleared and
retyped. Only the decimal/fractional LUNITS survived by accident.

New edit_angle row helper formats angles with format_angle
(AUNITS/AUPREC: decimal degrees, DMS, grads or radians), applied to all
17 angle rows (rotations, obliquing, arc start/end, hatch pattern
angle, multileader text rotation). parse_angle_deg converts every
AUNITS display form back to degrees ("30°"/"30d", DMS 30°15'20",
33.33g, 0.52r) and parse_f64 falls back to it, so the displayed value
round-trips through an edit.

Closes #297

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

src/entities/insert.rs

@@ -4,7 +4,7 @@ use acadrust::{EntityType, Handle};
 use glam::Vec3;
 
 use crate::command::EntityTransform;
-use crate::entities::common::{edit_prop as edit, parse_f64, ro_prop as ro, square_grip};
+use crate::entities::common::{edit_angle_prop as edit_angle, edit_prop as edit, parse_f64, ro_prop as ro, square_grip};
 
 use crate::scene::model::object::{GripApply, GripDef, PropSection, PropValue, Property};
 use crate::scene::model::wire_model::WireModel;
@@ -53,7 +53,7 @@ fn properties(ins: &Insert) -> Vec<PropSection> {
             title: "Misc".into(),
             props: vec![
                 ro("Name", "block", ins.block_name.clone()),
-                edit("Rotation", "rotation", ins.rotation.to_degrees()),
+                edit_angle("Rotation", "rotation", ins.rotation.to_degrees()),
                 ro(
                     "Annotative",
                     "annotative",