feat: middleware 적용, 오류페이지 추가, 일부 컴포넌트 파일명 변경, 리펙토링

[mental-disaster]

작업 내용

• gitignore 추가 (gemini)
• middleware 적용
• not found, error 오류페이지 및 테스트 코드 추가
• 컴포넌트 파일명 파스칼케이스로 변경
• /auction 페이지 리펙토링
  • categoryPath, setExpandedIds 분리
  • setExpandedIds 호출 -> findCategoryPath 호출 -> setExpandedIds 호출...의 무한 리렌더 오류 방지를 위해 useMemo 사용

[Copilot]

Pull Request Overview

Adds middleware, error handling pages, component filename casing updates, and refactors the auction preview page.

• Introduce middleware to redirect root path to the auction preview
• Rename auction components (category, list, search) to PascalCase and update related imports/tests
• Add 404 and error pages (with tests) and wire them into the app routes
• Refactor /ui-preview/auction/page.tsx to use useMemo for category path and eliminate infinite re-renders

Reviewed Changes

Copilot reviewed 17 out of 18 changed files in this pull request and generated no comments.

Show a summary per file

File	Description
src/middleware.ts	Add middleware redirect for root path
src/components/page/auction/Search.tsx	Rename component to PascalCase and export default
src/components/page/auction/Search.test.tsx	Update import path to PascalCase component
src/components/page/auction/List.tsx	Rename component to PascalCase and export default
src/components/page/auction/category.tsx	Rename component to PascalCase and export default
src/components/page/auction/category.test.tsx	Update import path to PascalCase component
src/components/errors/NotFoundPage.tsx	Add 404 not-found page component
src/components/errors/NotFoundPage.test.tsx	Add tests for 404 page
src/components/errors/ErrorPage.tsx	Add generic error page component
src/components/errors/ErrorPage.test.tsx	Add tests for error page
src/app/not-found.tsx	Route to NotFoundPage
src/app/error.tsx	Route to ErrorPage
src/app/(main)/ui-preview/error-test/page.tsx	Add UI preview test page for errors
src/app/(main)/ui-preview/auction/page.tsx	Refactor auction preview: useMemo for category path, update imports
src/app/(main)/ui-preview/auction/page.test.tsx	Update mocks to PascalCase imports
src/app/(main)/layout.tsx	Ensure main container fills height
src/app/login/page.test.tsx	Make document.referrer configurable in login page tests

Comments suppressed due to low confidence (2)

src/middleware.ts:4

• [nitpick] The TODO comment is vague; consider clarifying the intended behavior or removing it once requirements are locked down to avoid technical debt.

  // TODO: 추후 확인 후 수정 필요

src/middleware.ts:3

• There are no tests covering the middleware redirect logic. Adding a unit or integration test for the root-path redirection will help prevent regressions.

export function middleware(request: NextRequest) {