fix: sửa lỗi hiển thị thumbnail khi chia sẻ trên facebook

frontend/src/components/PublicPhotoModal.tsx

@@ -400,12 +400,20 @@ export const PublicPhotoModal: React.FC<PublicPhotoModalProps> = ({
               <span>{likeCount}</span>
             </button>
 
-            <img
-              src={photo.imageUrl}
-              alt="Public Map Upload"
-              className="w-full h-auto max-h-[85vh] object-contain cursor-zoom-in md:h-full md:max-h-none"
-              onClick={() => setIsFullscreen(true)}
-            />
+            <a
+              href={`${window.location.origin}/api/v1/public-photos/${photo.id}/share`}
+              className="w-full h-auto max-h-[85vh] object-contain cursor-zoom-in md:h-full md:max-h-none flex items-center justify-center"
+              onClick={(e) => {
+                e.preventDefault();
+                setIsFullscreen(true);
+              }}
+            >
+              <img
+                src={photo.imageUrl}
+                alt="Public Map Upload"
+                className="w-full h-auto max-h-[85vh] object-contain md:h-full md:max-h-none"
+              />
+            </a>
           </div>
 
           {/* Info & Timeline overlay inside photo panel */}