Function sweep_bend_profile 

pub fn sweep_bend_profile(
    profile: &[NurbsCurve],
    path: &SweepPath,
    stations: usize,
) -> Result<Vec<BendStation>, KernelRefusal>

The ρκ profile a TRANSPLANT sweep of profile along path would carry at stations stations — the instrument behind the refusal below, exposed so a caller (or a probe) can measure a path BEFORE asking for the solid.

Reads the very stations the sweep’s tight-bend refusal reads: the FLOOR budget, before the error-driven refinement (chain_stations) adds any — the same sampling, the same rotation-minimizing frame. A bend too tight is decided and quoted on the floor stations so that a path which folds is refused before stations are spent refining it, and so that the refusal’s numbers do not move with the tolerance. Untwisted, which is the lane every caller of sweep_profile_along_chain_with_stations is in.