[프론트엔드] <SideBar> 페이지 구현

## ISSUE
- Group: `client`
- Type: `feature`
- Detail: 페이지 구현

## TODO
- [ ] 로그인버튼
- [ ] 마이페이지버튼
- [ ] 물고기 자료버튼
- [ ] 회원 닉네임 위치 체크
- [ ] 금어기 버튼
- [ ] 체크리스트

## Estimated time
`1h`

## Labels
Estimated time: E: `1h`
Group : `client`
Sprint: `Sprint 1`
Urgency: `bare`

No source files, routes, or tests are named. Start by locating the client-side page components and existing sidebar or navigation patterns, then implement the listed login, my-page, fish-data, closed-season, checklist, and nickname elements; done means all TODO items are present and the page matches the project's existing frontend conventions.

Written by the indexing model from the issue text.