Function detect_referral_trigger 

pub fn detect_referral_trigger(quin: &NQuin) -> Option<ReferralTrigger>

Detect whether a claim Quin crosses an overriding referral threshold via an explicit high-liability predicate (acute harm / imminent jeopardy). Predicate-driven, like identify_degradation_vector. Returns None for ordinary analytical claims (those go through the Linguistic Degradation Matrix instead).