백업 관련 핫픽스

[sukchan-0811]

PR Title: 백업 관련 핫픽스

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PR Description:

백업 - 로그아웃 - 재로그인 시 즐겨찾기 및 Weight Table, 내가 만든 상징들이 제대로 백업되지 않는 이슈를 해결했습니다.
백업시 400 error가 반환될때 대응하도록 바꾸었습니다

Changes Included:

• Added new feature(s)
• Fixed identified bug(s)
• Updated relevant documentation

Notes for Reviewer:

Reviewer Checklist:

• Code is written in clean, maintainable, and idiomatic form.
• Automated test coverage is adequate.
• All existing tests pass.
• Manual testing has been performed to ensure the PR works as expected.
• Code review comments have been addressed or clarified.

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