refactor: 닉네임 반환 수정 (#251)

Author: Ssamssamukja

clokey-api/src/main/java/org/clokey/domain/feed/dto/response/FeedListResponse.java

@@ -26,7 +26,7 @@ public record FeedItemResponse(
     @Schema(name = "FeedAuthorResponse", description = "피드 작성자 정보")
     public record FeedAuthorResponse(
             @Schema(description = "작성자 ID", example = "1") Long memberId,
-            @Schema(description = "클로키 ID", example = "clokey123") String clokeyId,
+            @Schema(description = "닉네임", example = "codive123") String nickname,
             @Schema(description = "프로필 이미지 URL", example = "https://example.com/profile.jpg")
                     String profileImageUrl,
             @Schema(description = "팔로잉 여부", example = "true") boolean isFollowing) {}

clokey-api/src/main/java/org/clokey/domain/feed/service/FeedServiceImpl.java

@@ -168,7 +168,7 @@ public FeedListResponse getFeeds(
     private FeedListResponse.FeedAuthorResponse toAuthorResponse(
             Member member, boolean isFollowing) {
         return new FeedListResponse.FeedAuthorResponse(
-                member.getId(), member.getClokeyId(), member.getProfileImageUrl(), isFollowing);
+                member.getId(), member.getNickname(), member.getProfileImageUrl(), isFollowing);
     }
 
     private Map<Long, String> getImageUrls(List<Long> feedIds) {