Function build_check 

pub fn build_check(hint: &CheckHint, stdout: &str) -> Check

Map a check job’s stdout JSON object + its CheckHint into a KLP Check. Pure (no I/O) so it’s unit-testable. Non-JSON / non-object stdout, or a missing / unrecognised status_field, degrades to CheckStatus::Unknown with a diagnostic detail — everything else is up to the operator’s PowerShell.