Function evaluate_position_monitor 

pub async fn evaluate_position_monitor(
    market: &MarketDataApi,
    group: &OptionPositionGroup,
    rules: &RulesConfig,
    today: NaiveDate,
    tracked: Option<&TrackedPosition>,
) -> Result<PositionMonitorResult>

Evaluate mechanical exit rules and build an LLM-ready monitor snapshot (single chain fetch).