Dynamic dimensions: reference text format, horizontal text, lock after the text

A plain number shows as typed (d1=100), an expression under the fx: prefix
(fx: d2=d1*2); the text stays horizontal through DIMTIH/DIMTOH overrides
and the lock mark follows the text.

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

src/app/command_driver.rs

@@ -3611,6 +3611,7 @@ impl OpenCADStudio {
                 };
                 let text = dynamic_dimension_text(
                     &name,
+                    &expression,
                     value,
                     self.tabs[i].scene.constraint_name_format,
                 );