feat: 앨범 사진 다중 해상도 URL 지원 및 갤러리 UI 개선

- album_photos, album_teasers 테이블에 original_url, medium_url, thumb_url 컬럼 추가
- API에서 3가지 해상도 URL 및 width/height 반환
- AlbumDetail: 티저는 thumb_url(400), 컨셉포토는 medium_url(800) 사용
- AlbumGallery: 동적 비율 + CSS hover 효과 추가
- react-photo-album rowConstraints로 마지막 row 표시 문제 개선

backend/routes/albums.js

@@ -12,17 +12,18 @@ async function getAlbumDetails(album) {
   );
   album.tracks = tracks;
 
-  // 티저 이미지 조회
+  // 티저 이미지 조회 (3개 해상도 URL 포함)
   const [teasers] = await pool.query(
-    "SELECT image_url FROM album_teasers WHERE album_id = ? ORDER BY sort_order",
+    "SELECT original_url, medium_url, thumb_url FROM album_teasers WHERE album_id = ? ORDER BY sort_order",
     [album.id]
   );
-  album.teasers = teasers.map((t) => t.image_url);
+  album.teasers = teasers;
 
-  // 컨셉 포토 조회 (멤버 정보 포함)
+  // 컨셉 포토 조회 (멤버 정보 + 3개 해상도 URL + 크기 정보 포함)
   const [photos] = await pool.query(
     `SELECT 
-      p.id, p.photo_url, p.photo_type, p.concept_name, p.sort_order,
+      p.id, p.original_url, p.medium_url, p.thumb_url, p.photo_type, p.concept_name, p.sort_order,
+      p.width, p.height,
       GROUP_CONCAT(m.name ORDER BY m.id SEPARATOR ', ') as members
     FROM album_photos p
     LEFT JOIN album_photo_members pm ON p.id = pm.photo_id
@@ -42,7 +43,11 @@ async function getAlbumDetails(album) {
     }
     conceptPhotos[concept].push({
       id: photo.id,
-      url: photo.photo_url,
+      original_url: photo.original_url,
+      medium_url: photo.medium_url,
+      thumb_url: photo.thumb_url,
+      width: photo.width,
+      height: photo.height,
       type: photo.photo_type,
       members: photo.members,
       sortOrder: photo.sort_order,

frontend/src/pages/pc/AlbumDetail.jsx

@@ -110,18 +110,7 @@ function AlbumDetail() {
             });
     }, [name]);
 
-    // URL을 썸네일/원본 버전으로 변환하는 헬퍼
-    const getThumbUrl = (url) => {
-        const parts = url.split('/');
-        const filename = parts.pop();
-        return [...parts, 'thumb_400', filename].join('/');
-    };
-
-    const getOriginalUrl = (url) => {
-        const parts = url.split('/');
-        const filename = parts.pop();
-        return [...parts, 'original', filename].join('/');
-    };
+    // URL 헬퍼 함수는 더 이상 필요 없음 - API에서 직접 제공
 
     // 날짜 포맷팅
     const formatDate = (dateStr) => {
@@ -248,11 +237,11 @@ function AlbumDetail() {
                                     {album.teasers.map((teaser, index) => (
                                         <div 
                                             key={index}
-                                        onClick={() => setLightbox({ open: true, images: album.teasers.map(t => getOriginalUrl(t)), index })}
+                                        onClick={() => setLightbox({ open: true, images: album.teasers.map(t => t.original_url), index })}
                                             className="w-24 h-24 bg-gray-200 rounded-lg overflow-hidden cursor-pointer transition-all duration-200 hover:scale-110 hover:shadow-xl hover:z-10"
                                         >
                                             <img 
-                                                src={getThumbUrl(teaser)}
+                                                src={teaser.thumb_url}
                                                 alt={`Teaser ${index + 1}`}
                                                 className="w-full h-full object-cover"
                                             />
@@ -357,11 +346,11 @@ function AlbumDetail() {
                                     {previewPhotos.map((photo, idx) => (
                                         <div 
                                             key={photo.id}
-                                            onClick={() => setLightbox({ open: true, images: [getOriginalUrl(photo.url)], index: 0 })}
+                                            onClick={() => setLightbox({ open: true, images: [photo.original_url], index: 0 })}
                                             className="aspect-square bg-gray-200 rounded-xl overflow-hidden cursor-pointer transition-all duration-200 hover:scale-105 hover:shadow-xl hover:z-10"
                                         >
                                             <img 
-                                                src={getThumbUrl(photo.url)} 
+                                                src={photo.medium_url} 
                                                 alt={`컨셉 포토 ${idx + 1}`}
                                                 className="w-full h-full object-cover"
                                             />

frontend/src/pages/pc/AlbumGallery.jsx

@@ -5,6 +5,26 @@ import { X, ChevronLeft, ChevronRight, Download } from 'lucide-react';
 import { RowsPhotoAlbum } from 'react-photo-album';
 import 'react-photo-album/rows.css';
 
+// CSS로 호버 효과 추가 + overflow 문제 수정
+const galleryStyles = `
+.react-photo-album {
+    overflow: visible !important;
+}
+.react-photo-album--row {
+    overflow: visible !important;
+}
+.react-photo-album--photo {
+    transition: transform 0.3s ease, filter 0.3s ease !important;
+    cursor: pointer;
+    overflow: visible !important;
+}
+.react-photo-album--photo:hover {
+    transform: scale(1.05);
+    filter: brightness(0.9);
+    z-index: 10;
+}
+`;
+
 function AlbumGallery() {
     const { name } = useParams();
     const navigate = useNavigate();
@@ -15,57 +35,28 @@ function AlbumGallery() {
     const [imageLoaded, setImageLoaded] = useState(false);
     const [slideDirection, setSlideDirection] = useState(0);
 
-    // URL을 썸네일/원본 버전으로 변환하는 헬퍼
-    const getThumbUrl = (url) => {
-        // https://s3.../photo/01.webp → https://s3.../photo/thumb_400/01.webp
-        const parts = url.split('/');
-        const filename = parts.pop();
-        return [...parts, 'thumb_400', filename].join('/');
-    };
-
-    const getOriginalUrl = (url) => {
-        const parts = url.split('/');
-        const filename = parts.pop();
-        return [...parts, 'original', filename].join('/');
-    };
-
-    // 이미지 dimensions 로드
-    const loadImageDimensions = (url) => {
-        return new Promise((resolve) => {
-            const img = new Image();
-            img.onload = () => resolve({ width: img.naturalWidth, height: img.naturalHeight });
-            img.onerror = () => resolve({ width: 3, height: 4 }); // 기본 3:4 비율
-            img.src = url;
-        });
-    };
-
     useEffect(() => {
         fetch(`/api/albums/by-name/${name}`)
             .then(res => res.json())
-            .then(async data => {
+            .then(data => {
                 setAlbum(data);
                 const allPhotos = [];
                 
                 if (data.conceptPhotos && typeof data.conceptPhotos === 'object') {
                     Object.entries(data.conceptPhotos).forEach(([concept, photos]) => {
                         photos.forEach(p => allPhotos.push({ 
-                            thumbUrl: getThumbUrl(p.url),
-                            originalUrl: getOriginalUrl(p.url),
+                            // API에서 직접 제공하는 URL 및 크기 정보 사용
+                            mediumUrl: p.medium_url,
+                            originalUrl: p.original_url,
+                            width: p.width || 800,
+                            height: p.height || 1200,
                             title: concept,
                             members: p.members ? p.members.split(', ') : []
                         }));
                     });
                 }
                 
-                // 모든 이미지 dimensions 로드
-                const photosWithDimensions = await Promise.all(
-                    allPhotos.map(async (photo) => {
-                        const dims = await loadImageDimensions(photo.thumbUrl);
-                        return { ...photo, width: dims.width, height: dims.height };
-                    })
-                );
-                
-                setPhotos(photosWithDimensions);
+                setPhotos(allPhotos);
                 setLoading(false);
             })
             .catch(error => {
@@ -201,22 +192,25 @@ function AlbumGallery() {
                     <p className="text-gray-500 mt-1">{photos.length}장의 사진</p>
                 </div>
 
-                {/* Justified 갤러리 - react-photo-album */}
+                {/* CSS 스타일 주입 */}
+                <style>{galleryStyles}</style>
+                
+                {/* Justified 갤러리 - 동적 비율 + 호버 */}
                 <RowsPhotoAlbum
                     photos={photos.map((photo, idx) => ({
-                        src: photo.thumbUrl,
-                        width: photo.width || 300,
-                        height: photo.height || 400,
+                        src: photo.mediumUrl,
+                        width: photo.width || 800,
+                        height: photo.height || 1200,
                         key: idx.toString()
                     }))}
-                    targetRowHeight={300}
+                    targetRowHeight={280}
                     spacing={8}
+                    rowConstraints={{ singleRowMaxHeight: 400, minPhotos: 1 }}
                     onClick={({ index }) => openLightbox(index)}
                     componentsProps={{
-                        container: { style: { cursor: 'pointer' } },
                         image: { 
                             loading: 'lazy',
-                            style: { borderRadius: '8px', transition: 'transform 0.3s' }
+                            style: { borderRadius: '12px' }
                         }
                     }}
                 />