Function derive_sec_market 

pub fn derive_sec_market(
    ftapi_sec_market: i32,
    trd_market: i32,
    code: &str,
) -> i32

Derive FTAPI TrdSecMarket from explicit value, account market, and code.

Prefix and futures ticker fallback intentionally win over SDK supplied market, matching the established v1.4.56 behavior for futures symbols where client SDK market metadata can be stale or too generic.