feat(gallery): show folder names in gallery view (#3507)

Gallery items rendered folders as bare icons, indistinguishable from
one another. Folder tiles now carry a bottom name bar with a readable
gradient; loading placeholders excluded.

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Co-Authored-By: Devin <158243242+devin-ai-integration[bot]@users.noreply.github.com>

frontend/src/component/FileManager/Explorer/GalleryView/GalleryImage.tsx

@@ -173,6 +173,16 @@ const GalleryImage = memo((props: FileBlockProps) => {
           </Fade>
         )}
       </TransitionGroup>
+      {file.type == FileType.folder && !isLoadingIndicator && !file.placeholder && (
+        <ImageListItemBar
+          title={file.name}
+          position="bottom"
+          sx={{
+            background: "linear-gradient(to top, rgba(0,0,0,0.6) 0%, rgba(0,0,0,0.25) 60%, rgba(0,0,0,0) 100%)",
+            "& .MuiImageListItemBar-titleWrap": { px: 1 },
+          }}
+        />
+      )}
       <Fade in={!isLoadingIndicator && (hovered || !!isSelected)}>
         <ImageListItemBar
           sx={{