Upstream R-2 (round 17, 2026-07-28): the slots a per-node glyph
can occupy. Shared by the scene hit tester and the structural
SVG view's glyph rendering.
Type Declaration
"top-left"
"top-right"
"bottom-left"
"bottom-right"
"top"
"bottom"
"row"
R-11: a compartment row's own affordance, right-aligned in the
row band. Rows have no corners to choose between.
Upstream R-2 (round 17, 2026-07-28): the slots a per-node glyph can occupy. Shared by the scene hit tester and the structural SVG view's glyph rendering.