fix(dynin): read a comma-separated second point as cartesian, not W/H

A rectangle's opposite corner is entered through Width/Height dynamic
fields, whose sign is taken from the cursor quadrant on commit. Typing
"50,50" is a cartesian coordinate pair, not two cursor-signed
dimensions, but the comma advance kept the Width/Height roles so the
committed corner mirrored into whatever quadrant the cursor sat in.

Key off `dyn_user_reshaped` (set only by `,`, never by Tab) to treat a
comma-separated entry as a literal cartesian coordinate for every field,
in both the point resolver and the live dyn-box display. Tab-separated
entry still reads as signed Width/Height dimensions.

Closes #269

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

src/app/view/mod.rs

@@ -524,7 +524,13 @@ impl OpenCADStudio {
                             {
                                 format!("{lv:.4}")
                             }
-                            _ => dyn_component_value(f, w, base, &tab.ucs_xform()),
+                            _ => dyn_component_value(
+                                f,
+                                w,
+                                base,
+                                &tab.ucs_xform(),
+                                self.dyn_user_reshaped,
+                            ),
                         };
                         crate::ui::overlay::DynBox {
                             label: f.role.label().to_string(),