fix: update root/repo_id path in lerobot_dataset.py

src/lerobot/datasets/lerobot_dataset.py

@@ -512,7 +512,7 @@ def create(
         """Creates metadata for a LeRobotDataset."""
         obj = cls.__new__(cls)
         obj.repo_id = repo_id
-        obj.root = Path(root) if root is not None else HF_LEROBOT_HOME / repo_id
+        obj.root = Path(root) / repo_id if root is not None else HF_LEROBOT_HOME / repo_id
 
         obj.root.mkdir(parents=True, exist_ok=False)
 
@@ -690,7 +690,7 @@ def __init__(
         if vcodec not in VALID_VIDEO_CODECS:
             raise ValueError(f"Invalid vcodec '{vcodec}'. Must be one of: {sorted(VALID_VIDEO_CODECS)}")
         self.repo_id = repo_id
-        self.root = Path(root) if root else HF_LEROBOT_HOME / repo_id
+        self.root = Path(root) / repo_id if root else HF_LEROBOT_HOME / repo_id
         self.image_transforms = image_transforms
         self.delta_timestamps = delta_timestamps
         self.episodes = episodes
@@ -713,7 +713,7 @@ def __init__(
 
         # Load metadata
         self.meta = LeRobotDatasetMetadata(
-            self.repo_id, self.root, self.revision, force_cache_sync=force_cache_sync
+            self.repo_id, root, self.revision, force_cache_sync=force_cache_sync
         )
 
         # Track dataset state for efficient incremental writing