✨ Feat: 테마 정보 -> DTO 컨버터 구현

Builder 패턴을 활용한 변환 코드 작성

- 관련 : #427

application/external-api-v2/src/main/java/com/namo/spring/application/external/api/shop/converter/ThemeConverter.java

@@ -7,6 +7,7 @@
 
 import com.namo.spring.application.external.api.shop.dto.ThemeResponse;
 import com.namo.spring.db.mysql.domains.shop.entity.Theme;
+import com.namo.spring.db.mysql.domains.shop.entity.ThemeDetailImage;
 
 public class ThemeConverter {
 
@@ -33,4 +34,19 @@ public static ThemeResponse.ThemePreviewDto toThemeResponseDto(Theme theme) {
             .previewImageUrl(theme.getPreviewImageUrl())
             .build();
     }
+
+    public static ThemeResponse.ThemeInfoDto toThemeInfoDto(Theme theme) {
+        List<String> detailImages = theme.getDetailImages().stream()
+            .map(ThemeDetailImage::getImageUrl)
+            .toList();
+
+        return ThemeResponse.ThemeInfoDto.builder()
+            .id(theme.getId())
+            .name(theme.getName())
+            .description(theme.getDescription())
+            .price(theme.getPrice())
+            .detailImages(detailImages)
+            .isOwned(theme.isOwned())
+            .build();
+    }
 }

application/external-api-v2/src/main/java/com/namo/spring/application/external/api/shop/service/ThemeManageService.java

@@ -23,11 +23,24 @@ public class ThemeManageService {
     private final ThemeService themeService;
     private final MemberThemeService memberThemeService;
 
+    /**
+     * 테마 타입에 따른 테마 목록을 반환 합니다.
+     * @param themeType (프로필, 배경)
+     * @param page
+     * @param size
+     * @return
+     */
     public Page<Theme> getSellingThemesByType(ThemeType themeType, int page, int size) {
         Pageable pageable = PageRequest.of(page - 1, size);
         return themeService.findByTypeAndStatus(themeType, pageable, ThemeStatus.SELLING);
     }
 
+    /**
+     * 테마 정보와 소유 여부를 반환 합니다.
+     * @param memberId
+     * @param themeId
+     * @return
+     */
     public Theme getThemeByIdWithOwnership(Long memberId, Long themeId) {
         Theme theme = themeService.findByIdAndStatus(themeId, ThemeStatus.SELLING)
                 .orElseThrow(() -> new ThemeException(ErrorStatus.NOT_FOUND_THEME));