nextMastery static method
Returns the next mastery level if the completed session mode matches the expected progression, or null if no advancement applies.
Implementation
static String? nextMastery(String current, String sessionMode) {
return switch ((current, sessionMode)) {
('awareness', 'socratic' || 'teach') => 'understanding',
('understanding', 'quiz') => 'application',
('application', 'code_review' || 'confused_student') => 'evaluation',
_ => null,
};
}