fix(view): window corner picks exempt from Ortho/Polar (#363)

ZOOM WINDOW's opposite corner was pinned to an axis with Ortho on,
collapsing the window to a line. Extend the #291 window_corner_pick
exemption to ZOOM WINDOW, PLOTWINDOW and WIPEOUT's rectangular mode
(polygon mode keeps the constraints — axis-aligned edges are a
legitimate use).

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

src/modules/draw/draw/wipeout.rs

@@ -107,6 +107,13 @@ impl CadCommand for WipeoutCommand {
         }
     }
 
+    fn window_corner_pick(&self) -> bool {
+        // Rectangular mode picks free window corners — exempt from Ortho/Polar
+        // (#363/#291 class). Polygon points keep the constraints (axis-aligned
+        // polygon edges are a legitimate use).
+        matches!(self.mode, WipeoutMode::Rectangular)
+    }
+
     fn on_mouse_move(&mut self, pt: DVec3) -> Option<WireModel> { let pt = pt.as_vec3();
         match &self.mode {
             WipeoutMode::Rectangular => {

src/modules/view/plot_window.rs

@@ -44,6 +44,11 @@ impl CadCommand for PlotWindowCommand {
         CmdResult::Cancel
     }
 
+    fn window_corner_pick(&self) -> bool {
+        // Free rectangle corners — exempt from Ortho/Polar (#363/#291 class).
+        true
+    }
+
     fn on_mouse_move(&mut self, pt: DVec3) -> Option<WireModel> { let pt = pt.as_vec3();
         let p1 = self.p1?.as_vec3();
         // Draw the selection rectangle.

src/modules/view/zoom_window.rs

@@ -59,6 +59,13 @@ impl CadCommand for ZoomWindowCommand {
         CmdResult::Cancel
     }
 
+    fn window_corner_pick(&self) -> bool {
+        // Both zoom-window corners are free points; Ortho/Polar must not pin
+        // the opposite corner to an axis or the window collapses to a line
+        // (#363, same class as #291).
+        true
+    }
+
     fn on_mouse_move(&mut self, pt: DVec3) -> Option<WireModel> { let pt = pt.as_vec3();
         let p1 = self.first?;
         let min = p1.min(pt);