Function resolve_reg_qot_push_securities 

pub fn resolve_reg_qot_push_securities<F>(
    securities: &[Security],
    lookup_stock_id: F,
) -> Result<Vec<RegQotPushResolvedSecurity>, String>
where
    F: FnMut(&str) -> RegQotPushLookup,

Resolve Qot_RegQotPush.security_list to cache keys and stock ids.

Unlike Qot_Sub, C++ RegQotPush resolves the submitted Qot_Common::Security as-is and does not apply the TrdMarket compatibility mapping. The caller supplies a cache lookup closure so this pure domain helper stays independent from futu-cache.