M3.97: freeform points drag out to delete, spread ring drags, Lines mode draws lines

With the Gradient tool on a freeform gradient the selected point shows its
spread as a dashed ring with a handle; dragging either sets the spread. A
point dragged out of the object is removed on release, and double-clicking a
point opens the gradientStop popover, which now edits the selected freeform
point (colour, opacity, spread). In Lines mode successive clicks draw one
smooth line (with a rubber band to the pointer); clicking an existing point
continues the line from it, and Escape or a click off the art ends it.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

crates/engine/src/cmd/gradient.rs

@@ -357,7 +357,7 @@ fn edit_gradient(s: &mut Session, p: &Value) -> Result<Value> {
         }
         let b = item_paint_bounds(n, index, !stroke);
         // Only a gradient turning freeform needs the shape (its first points go inside it).
-        let inside = (freeform && b.is_some()).then(|| super::freeform::inside_fn(n));
+        let inside = (freeform && b.is_some()).then(|| n.contains_fn());
         let inside: &dyn Fn(Point) -> bool = match &inside {
             Some(f) => f,
             None => &|_| true,