리팩터링

컬렉션을 사용해 정리하기 내 환경설정을 기준으로 콘텐츠를 저장하고 분류하세요.

Refactor the Kotlin code below to be more idiomatic, efficient, and readable. Focus on
using Kotlin's features like extension functions, data classes, sealed classes, and
coroutines where appropriate. Explain the changes you made and why they improve the
code. Also, suggest potential performance optimizations.

$CURRENT_FILE