Function is_valid_qot_market 

pub fn is_valid_qot_market(market: i32) -> bool

Whether a public Qot_Common.QotMarket value is accepted by Qot_Sub.

This intentionally mirrors the historical gateway gate exactly. RegQotPush also uses this predicate, but does not use normalize_qot_sub_market because C++ RegQotPush resolves the submitted Qot_Common::Security as-is. Ref: proto/Qot_Common.proto:8-21.