[refactor] 이미지 저장 로직 수정

[hodoon]

[refactor]이미지 저장 로직 수정

Issue

• [refactor] 이미지 저장 로직 수정 #90

변경 내용

• Cloudflare r2 스토리지와 연동하여 뉴스 생성시 이미지는 클라우드 스토리지에 업로드 하도록 변경

체크리스트

• 커밋 메시지가 컨벤션을 따르는가?
• 로컬에서 빌드가 성공하는가?

테스트

• 로컬에서 테스트 완료
• 기존 기능에 영향 없음 확인
• 다양한 브라우저에서 테스트 (필요시)

[ysw789]

확인했습니다 Actions Secrets에 env 제대로 적용되었는지만 추가로 확인해주세요

[Copilot]

Pull Request Overview

This PR refactors the image storage logic to integrate with Cloudflare R2 storage instead of storing Base64-encoded files in the database. The change improves performance and scalability by moving file storage to cloud infrastructure.

• Replaced Base64 file encoding with Cloudflare R2 cloud storage integration
• Updated file entities to store URLs instead of encoded data
• Modified file upload API to return created file information

Reviewed Changes

Copilot reviewed 8 out of 9 changed files in this pull request and generated 1 comment.

Show a summary per file

File	Description
application-credentials.yml	Added Cloudflare R2 configuration properties
FileService.java	Refactored to use R2Service for file operations and return upload results
FileEntity.java	Changed from storing encoded data to file URLs
FileResponseDto.java	Updated field descriptions and order for URL-based storage
AdminFileController.java	Modified upload endpoint to return created file information
R2Service.java	New service for Cloudflare R2 file operations
R2Config.java	Configuration for AWS S3 client to work with Cloudflare R2
ErrorCode.java	Updated error message from encoding to upload failure

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