Cursors: 36 more tool states get cursors of their own, listed in cursors.toml

Node editing as the public manual describes it: Direct Selection's anchor squares (hollow
or filled), Reshape Segment over a curved segment, Group Selection's plus (also Direct
Selection with Alt), the arrow hollow while a drag snaps, and Alt-copy arrowheads. The
Anchor Point caret, the Curvature pen and Free Transform's side-shear arrows (ShearH,
ShearV) are drawn in code. Lasso, the freehand, symbolism and other tools return cursors
of their own that borrow their old look until drawn (Cursor::stand_in).

crates/tools/src/cursors.toml lists every Cursor value, when it shows and its hotspot,
for whoever draws them; `cargo xtask cursors` (in ci) warns about a missing, unknown,
repeated or incomplete entry and never fails. The busy cursor is listed as missing (G1).

Co-Authored-By: Claude Opus 5.5 (1M context) <noreply@anthropic.com>

crates/engine/tests/pen_endpoint_picking.rs

@@ -102,7 +102,7 @@ fn alt_at_another_endpoint_reports_conversion_and_preserves_objects_through_undo
     assert_eq!(node(&s, b), &before_b);
     assert_eq!(s.doc().unwrap().history.undo.len(), before_undo + 1);
     // Check the captured cursor last: a mismatch must not hide the actual conversion/history controls.
-    assert_eq!(advertised, Cursor::PenConvert, "Alt cursor must describe the conversion actually performed, not Join");
+    assert_eq!(advertised, Cursor::AnchorPoint, "Alt cursor must describe the conversion actually performed, not Join");
 }
 
 #[test]