Function gate_for_model 

pub fn gate_for_model(
    class: DisclosureClass,
    text: &str,
    consent_granted: bool,
    redactor: Option<&dyn Fn(&str) -> String>,
) -> ModelVisibility

THE model-visibility gate (spec §9.7). consent_granted is per-item explicit consent; redactor transforms text for the after-redaction class. Missing prerequisites fail closed.