M3.76: Attributes panel with overprint, centre point, path direction, fill rule, image map, URL and note

Window > Attributes (Cmd+F11) shows Overprint Fill/Stroke, Show/Don't Show
Center, Reverse Path Direction Off/On, the non-zero / even-odd fill rule,
Image Map, a URL field with recent URLs and a Browser button, and a note.
New commands attributes.set and path.setFillRule; path.reverse takes ids and
reversed; attributes.info reports every value. Objects keep the attributes in
Node.attrs. SVG export wraps linked objects in <a>, and import reads links
back. The canvas draws the centre point of selected objects that show it.

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

crates/engine/src/cmd/mod.rs

@@ -1,6 +1,7 @@
 //! The command registry. Ids follow Illustrator's menu structure.
 
 pub(crate) mod appearance;
+mod attributes;
 mod brushsym;
 mod buildcmds;
 pub mod clipboard;
@@ -204,6 +205,7 @@ pub fn command_specs() -> &'static [CommandSpec] {
         v.extend(flatten::specs());
         v.extend(stylelib::specs());
         v.extend(expand::specs());
+        v.extend(attributes::specs());
         v
     })
 }