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/update/dynamic.rs

@@ -212,8 +212,15 @@ impl OpenCADStudio {
             .unwrap_or(glam::Vec3::ZERO);
         // Buffer value parsed as f32 (de-scaled by the role so a typed diameter
         // becomes a radius), or the supplied geometric live value. Width/Height
-        // are shown unsigned, so a typed value takes the sign of the cursor's
+        // are shown unsigned, so a typed value normally takes the sign of the
-        // delta on that axis (`live` is the signed delta in the cartesian arms).
+        // cursor's delta on that axis (`live` is the signed delta in the
+        // cartesian arms). But once the user separates the two values with `,`
+        // — e.g. the rectangle opposite corner entered as "50,50" — the entry
+        // is a cartesian coordinate pair, not cursor-signed W/H dimensions, so
+        // the typed sign must stay literal. `,` is the only thing that sets
+        // `dyn_user_reshaped`, so it cleanly distinguishes comma-cartesian entry
+        // from Tab-separated dimension entry (#269).
+        let comma_cartesian = self.dyn_user_reshaped;
         let val = |idx: usize, live: f32| -> f32 {
             match fields[idx]
                 .buffer
@@ -226,7 +233,8 @@ impl OpenCADStudio {
                     if matches!(
                         fields[idx].role,
                         crate::command::DynRole::Width | crate::command::DynRole::Height
-                    ) {
+                    ) && !comma_cartesian
+                    {
                         v.abs().copysign(live)
                     } else {
                         v

src/app/view/controls.rs

@@ -194,6 +194,7 @@ pub(super) fn dyn_component_value(
     w: glam::Vec3,
     base: Option<glam::Vec3>,
     xf: &super::super::helpers::UcsXform,
+    comma_cartesian: bool,
 ) -> String {
     if let Some(b) = &f.buffer {
         return b.clone();
@@ -211,8 +212,12 @@ pub(super) fn dyn_component_value(
     // coordinate use the same frame. See #35.
     let has_base = base.is_some();
     // Width / Height read as unsigned magnitudes (the sign is taken from the
-    // cursor side on commit), matching the rectangle's two-edge entry.
+    // cursor side on commit), matching the rectangle's two-edge entry. But once
-    let wh = matches!(f.role, crate::command::DynRole::Width | crate::command::DynRole::Height);
+    // the user separates the values with `,` the entry is a cartesian
+    // coordinate pair, so the fields read as signed X/Y deltas to match the
+    // committed point (#269).
+    let wh = matches!(f.role, crate::command::DynRole::Width | crate::command::DynRole::Height)
+        && !comma_cartesian;
     match f.component {
         DynComponent::X if has_base => format!("{:.4}", if wh { dx.abs() } else { dx }),
         DynComponent::Y if has_base => format!("{:.4}", if wh { dy.abs() } else { dy }),

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(),