Merge pull request 'docs: 릴리즈 노트 정리 (2026-04-13)' (#37) from chore/release-notes-2026-04-13 into develop

docs/RELEASE-NOTES.md

@@ -6,6 +6,8 @@ The format is based on [Keep a Changelog](https://keepachangelog.com/ko/1.0.0/).
 
 ## [Unreleased]
 
+## [2026-04-13]
+
 ### 추가
 
 - 로그인 프로세스 제거 + ADMIN/MANAGER/USER 역할 토글 버튼 (#35)