Optionaloptions: {OptionalglyphAt?: (elementId: string, point: HitPoint) => GlyphSlot | null | undefinedR-2 (round 17, 2026-07-28): the VIEW owns glyph geometry (it draws them), so it supplies a probe rather than core duplicating the layout math. Returning a slot for a point makes that point a "glyph" hit, tested ABOVE the header so the affordance is reachable.
Structural-document hit test (StructuralSvgView): container header vs body vs border, rows, ports, routed edge segments.