pub const EXTENDED_RANK_FLOOR: f64 = 1e-6;Expand description
Smallest min|λ| / κ of H = II_a − II_b at which the contact counts as
an isolated node or point rather than EXTENDED along H’s null direction.
The same number csg/imprint/tangent_contact.rs reads: genuine nodes
measure 0.7..1.0, extended contacts 1e-15 and below, so this is a rank
test, not a tolerance band.