fn improves_on(
attained: &ExistingAttainment,
context: &SubmissionContext,
enrolment_grade_scale_id: Option<&str>,
) -> boolExpand description
Whether the grade we would send beats the one the registry already holds for this course unit.
Anything else — equal, worse, or a grade on a scale that does not rank against the held one — is false, so the duplicate guard stands and no second attainment can reach a transcript on a guess.