//! Sharpe collapse at fold boundary < 50%.
#[test]
#[ignore = "Phase 2B contract — green via existing StateResetRegistry"]
fn test_2_15_fold_transition_stability() {
    // Train on synthetic fold 1; capture sharpe at end. Reset state. Train fold 2;
    // capture sharpe at start. assert!((end - start).abs() / end.max(0.01) < 0.50);
    //
    // Phase 2B.b: requires fold-boundary scaffolding the harness doesn't yet expose.
}
