fix(fe): track latest plag request with id

[hjkim24]

Description

#3617 에서 새로 생성된 요청이 폴링 쿼리에 반영되기 전, 최신 요청이 completed인 경우 요청 성공 여부에 관계없이 완료 메세지가 나오게 되므로, 생성 요청을 id 기반으로 추적하도록 수정합니다.

Additional context

---

Before submitting the PR, please make sure you do the following

• Read the Contributing Guidelines
• Read the Contributing Guidelines and follow the Commit Convention
• Provide a description in this PR that addresses what the PR is solving, or reference the issue that it solves (e.g. fixes #123).
• Ideally, include relevant tests that fail without this PR but pass with it.

[gemini-code-assist]

Code Review

This pull request introduces a race condition guard in the plagiarism check polling mechanism by tracking the specific check request ID created by the current trigger, rather than simply tracking the latest request. Feedback was provided regarding a TypeScript type mismatch where the currentCheckId state is defined as string | null but should be number | null to match the GraphQL schema's Int type for the id field, preventing potential compilation and comparison errors.

Important

The consumer version of Gemini Code Assist on GitHub is being sunset. Starting June 18, 2026, new organization installations will be blocked, and all code review activity will officially cease on July 17, 2026.
For more details on the timeline and next steps, please review the Help Documentation.

[seoeun9]

수고하셨습니다~!!
주석은 머지 전에 지워주세요!