Function parse_instrument_statuses 

pub fn parse_instrument_statuses(
    market_id: &str,
    def: &MarketDefinition,
    ts_event: UnixNanos,
    ts_init: UnixNanos,
) -> Vec<InstrumentStatus>

Produces per-runner [InstrumentStatus] events from a market definition.

Iterates def.runners and maps each runner’s lifecycle to a Nautilus status. Scratched runners (Removed, RemovedVacant) close immediately regardless of market-level state. The in_play flag distinguishes pre-open (Open + not in play) from active trading (Open + in play).

Returns an empty vector when def.status or def.runners is missing.