pub const QUERY_MARGIN: f32 = _; // 30f32Expand description
How far a shape’s footprint can extend past its gui_rect from fixed-size
decorations: a pin stub reaches one GRID_SIZE out, and the widest point-snap
margin (ROUTE_HIT_MARGIN, ~0.9 grid) plus the tag rise sit within two cells.
Query rects are expanded by this before testing, and every indexed bound
already includes it.