feat: Implement sub-room functionality

- Added support for sub-rooms in the SpaceHierarchy component, allowing rooms to have nested child rooms.
- Introduced UnjoinedSubRoomItem component to display unjoined sub-rooms with a join button.
- Created SubRooms settings page for managing sub-rooms, including adding and removing sub-rooms.
- Updated RoomNavItem to include options for creating sub-rooms.
- Enhanced room fetching logic to filter out sub-rooms from the main room list.
- Added hooks for managing sub-rooms state and permissions.
- Updated relevant state management to handle sub-room creation and association with parent rooms.

src/app/components/image-viewer/ImageViewer.tsx

@@ -22,8 +22,23 @@ export const ImageViewer = as<'div', ImageViewerProps>(
     const { pan, cursor, onMouseDown } = usePan(zoom !== 1);
 
     const handleDownload = async () => {
-      const fileContent = await downloadMedia(src, mx.getAccessToken());
-      FileSaver.saveAs(fileContent, alt);
+      try {
+        const fileContent = await downloadMedia(src, mx.getAccessToken());
+        FileSaver.saveAs(fileContent, alt);
+      } catch (error) {
+        console.warn('[ImageViewer] Failed to download media:', error);
+        // Fallback: try to fetch via standard fetch as blob
+        try {
+          const response = await fetch(src);
+          if (response.ok) {
+            const blob = await response.blob();
+            FileSaver.saveAs(blob, alt);
+          }
+        } catch {
+          // If all else fails, open in new tab to let browser handle it
+          window.open(src, '_blank');
+        }
+      }
     };
 
     return (