feat: 앨범 상세 페이지 컨셉 포토 라이트박스 개선

- PC/Mobile 앨범 상세 페이지 컨셉 포토 라이트박스에서 좌우 네비게이션 지원
- 현재 보이는 미리보기 사진 내에서만 네비게이션 (PC 4장, Mobile 6장)
- 컨셉 이름과 멤버 정보 표시 (AlbumGallery와 동일한 UX)
- lightbox state에 photos 배열 추가하여 메타데이터 관리

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

frontend-temp/src/pages/album/mobile/AlbumDetail.jsx

@@ -27,7 +27,7 @@ import { LightboxIndicator } from '@/components/common';
 function MobileAlbumDetail() {
   const { name } = useParams();
   const navigate = useNavigate();
-  const [lightbox, setLightbox] = useState({ open: false, images: [], index: 0, showNav: true, teasers: null });
+  const [lightbox, setLightbox] = useState({ open: false, images: [], index: 0, showNav: true, teasers: null, photos: null });
   const [showAllTracks, setShowAllTracks] = useState(false);
   const [showDescriptionModal, setShowDescriptionModal] = useState(false);
   const swiperRef = useRef(null);
@@ -47,6 +47,7 @@ function MobileAlbumDetail() {
       index,
       showNav: options.showNav !== false,
       teasers: options.teasers,
+      photos: options.photos || null,
     });
     window.history.pushState({ lightbox: true }, '');
   }, []);
@@ -123,7 +124,24 @@ function MobileAlbumDetail() {
     );
   }
 
-  const allPhotos = album.conceptPhotos ? Object.values(album.conceptPhotos).flat() : [];
+  // 컨셉 정보를 포함한 사진 배열 생성
+  const allPhotosWithInfo = [];
+  if (album.conceptPhotos) {
+    Object.entries(album.conceptPhotos).forEach(([concept, conceptPhotos]) => {
+      conceptPhotos.forEach((p) =>
+        allPhotosWithInfo.push({
+          ...p,
+          originalUrl: p.original_url,
+          mediumUrl: p.medium_url,
+          thumbUrl: p.thumb_url,
+          title: concept,
+          members: p.members || '',
+        })
+      );
+    });
+  }
+  const previewCount = 6;
+  const previewPhotos = allPhotosWithInfo.slice(0, previewCount);
   const displayTracks = showAllTracks ? album.tracks : album.tracks?.slice(0, 5);
 
   return (
@@ -276,7 +294,7 @@ function MobileAlbumDetail() {
         )}
 
         {/* 컨셉 포토 */}
-        {allPhotos.length > 0 && (
+        {previewPhotos.length > 0 && (
           <motion.div
             initial={{ opacity: 0, y: 20 }}
             animate={{ opacity: 1, y: 0 }}
@@ -285,14 +303,20 @@ function MobileAlbumDetail() {
           >
             <p className="text-sm font-semibold mb-3">컨셉 포토</p>
             <div className="grid grid-cols-3 gap-2">
-              {allPhotos.slice(0, 6).map((photo, idx) => (
+              {previewPhotos.map((photo, idx) => (
                 <div
                   key={photo.id}
-                  onClick={() => openLightbox([photo.original_url], 0, { showNav: false })}
+                  onClick={() =>
+                    openLightbox(
+                      previewPhotos.map((p) => p.originalUrl),
+                      idx,
+                      { showNav: true, photos: previewPhotos }
+                    )
+                  }
                   className="aspect-square bg-gray-100 rounded-xl overflow-hidden shadow-sm"
                 >
                   <img
-                    src={photo.thumb_url || photo.medium_url}
+                    src={photo.thumbUrl || photo.mediumUrl}
                     alt={`컨셉 포토 ${idx + 1}`}
                     loading="lazy"
                     className="w-full h-full object-cover"
@@ -305,7 +329,7 @@ function MobileAlbumDetail() {
               onClick={() => navigate(`/album/${name}/gallery`)}
               className="w-full mt-3 py-3 text-sm text-primary font-medium bg-primary/5 rounded-xl flex items-center justify-center gap-1"
             >
-              전체 {allPhotos.length}장 보기
+              전체 {allPhotosWithInfo.length}장 보기
               <ChevronRight size={16} />
             </button>
           </motion.div>
@@ -403,11 +427,11 @@ function MobileAlbumDetail() {
             >
               {lightbox.images.map((url, index) => (
                 <SwiperSlide key={index} virtualIndex={index}>
-                  <div className="w-full h-full flex items-center justify-center">
+                  <div className="w-full h-full flex flex-col items-center justify-center">
                     {lightbox.teasers?.[index]?.media_type === 'video' ? (
                       <video
                         src={url}
-                        className="max-w-full max-h-full object-contain"
+                        className="max-w-full max-h-[70vh] object-contain"
                         controls
                         autoPlay={index === lightbox.index}
                       />
@@ -415,10 +439,41 @@ function MobileAlbumDetail() {
                       <img
                         src={url}
                         alt=""
-                        className="max-w-full max-h-full object-contain"
+                        className="max-w-full max-h-[70vh] object-contain"
                         loading={Math.abs(index - lightbox.index) <= 2 ? 'eager' : 'lazy'}
                       />
                     )}
+                    {/* 컨셉 포토 정보 (멤버 + 컨셉) */}
+                    {lightbox.photos && (() => {
+                      const photo = lightbox.photos[index];
+                      const title = photo?.title;
+                      const hasValidTitle = title && title.trim() && title !== 'Default';
+                      const members = photo?.members;
+                      const hasMembers = members && String(members).trim();
+
+                      if (!hasValidTitle && !hasMembers) return null;
+
+                      return (
+                        <div className="mt-4 flex flex-col items-center gap-2 px-4">
+                          {hasValidTitle && (
+                            <span className="px-3 py-1.5 bg-white/10 backdrop-blur-sm rounded-full text-white font-medium text-sm">
+                              {title}
+                            </span>
+                          )}
+                          {hasMembers && (
+                            <div className="flex flex-wrap items-center justify-center gap-1.5">
+                              {String(members)
+                                .split(',')
+                                .map((member, idx) => (
+                                  <span key={idx} className="px-2.5 py-1 bg-primary/80 rounded-full text-white text-xs">
+                                    {member.trim()}
+                                  </span>
+                                ))}
+                            </div>
+                          )}
+                        </div>
+                      );
+                    })()}
                   </div>
                 </SwiperSlide>
               ))}

frontend-temp/src/pages/album/pc/AlbumDetail.jsx

@@ -23,7 +23,7 @@ import { LightboxIndicator } from '@/components/common';
 function PCAlbumDetail() {
   const { name } = useParams();
   const navigate = useNavigate();
-  const [lightbox, setLightbox] = useState({ open: false, images: [], index: 0, teasers: null });
+  const [lightbox, setLightbox] = useState({ open: false, images: [], index: 0, teasers: null, photos: null });
   const [slideDirection, setSlideDirection] = useState(0);
   const [imageLoaded, setImageLoaded] = useState(false);
   const [preloadedImages] = useState(() => new Set());
@@ -60,7 +60,7 @@ function PCAlbumDetail() {
 
   // 라이트박스 열기
   const openLightbox = useCallback((images, index, options = {}) => {
-    setLightbox({ open: true, images, index, teasers: options.teasers });
+    setLightbox({ open: true, images, index, teasers: options.teasers, photos: options.photos || null });
     window.history.pushState({ lightbox: true }, '');
   }, []);
 
@@ -387,9 +387,22 @@ function PCAlbumDetail() {
               className="mt-10"
             >
               {(() => {
-                const allPhotos = Object.values(album.conceptPhotos).flat();
+                // 컨셉 정보를 포함한 사진 배열 생성
-                const previewPhotos = allPhotos.slice(0, 4);
+                const allPhotosWithInfo = [];
-                const totalCount = allPhotos.length;
+                Object.entries(album.conceptPhotos).forEach(([concept, conceptPhotos]) => {
+                  conceptPhotos.forEach((p) =>
+                    allPhotosWithInfo.push({
+                      ...p,
+                      originalUrl: p.original_url,
+                      mediumUrl: p.medium_url,
+                      title: concept,
+                      members: p.members || '',
+                    })
+                  );
+                });
+                const previewCount = 4;
+                const previewPhotos = allPhotosWithInfo.slice(0, previewCount);
+                const totalCount = allPhotosWithInfo.length;
 
                 return (
                   <>
@@ -406,11 +419,17 @@ function PCAlbumDetail() {
                       {previewPhotos.map((photo, idx) => (
                         <div
                           key={photo.id}
-                          onClick={() => openLightbox([photo.original_url], 0)}
+                          onClick={() =>
+                            openLightbox(
+                              previewPhotos.map((p) => p.originalUrl),
+                              idx,
+                              { photos: previewPhotos }
+                            )
+                          }
                           className="aspect-square bg-gray-200 rounded-xl overflow-hidden cursor-pointer transition-all duration-300 ease-out hover:scale-[1.03] hover:shadow-xl hover:z-10"
                         >
                           <img
-                            src={photo.medium_url}
+                            src={photo.mediumUrl}
                             alt={`컨셉 포토 ${idx + 1}`}
                             loading="lazy"
                             className="w-full h-full object-cover"
@@ -506,6 +525,37 @@ function PCAlbumDetail() {
                     transition={{ duration: 0.25, ease: 'easeOut' }}
                   />
                 )}
+                {/* 컨셉 포토 정보 (멤버 + 컨셉) */}
+                {imageLoaded && lightbox.photos && (() => {
+                  const photo = lightbox.photos[lightbox.index];
+                  const title = photo?.title;
+                  const hasValidTitle = title && title.trim() && title !== 'Default';
+                  const members = photo?.members;
+                  const hasMembers = members && String(members).trim();
+
+                  if (!hasValidTitle && !hasMembers) return null;
+
+                  return (
+                    <div className="mt-6 flex flex-col items-center gap-2">
+                      {hasValidTitle && (
+                        <span className="px-4 py-2 bg-white/10 backdrop-blur-sm rounded-full text-white font-medium text-base">
+                          {title}
+                        </span>
+                      )}
+                      {hasMembers && (
+                        <div className="flex items-center gap-2">
+                          {String(members)
+                            .split(',')
+                            .map((member, idx) => (
+                              <span key={idx} className="px-3 py-1.5 bg-primary/80 rounded-full text-white text-sm">
+                                {member.trim()}
+                              </span>
+                            ))}
+                        </div>
+                      )}
+                    </div>
+                  );
+                })()}
               </div>
 
               {/* 다음 버튼 */}