swaits
da9baf0325
`pareto_front` returns all candidates not dominated by any other in input order (O(N²·M), acceptable for v1 per spec §9.3). `best_candidate` is the single-objective "best" finder: returns None unless there is exactly one objective; ignores infeasibles; returns None if every candidate is infeasible (spec §9.4). Both re-exported from the prelude.