refactor(jobs): hoist LeRobotDataset import, guard dataset extra at package init

Move the `from lerobot.datasets import LeRobotDataset` import to the top of
dataset.py and relocate the `require_package("datasets", extra="dataset")`
guard to the jobs package __init__, per review feedback.

src/lerobot/jobs/__init__.py

@@ -12,6 +12,12 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
+from lerobot.utils.import_utils import require_package
+
+# LeRobotDataset (imported at module top in dataset.py) pulls in heavy dataset deps;
+# guard the optional dependency here so importing this package fails loudly if it's missing.
+require_package("datasets", extra="dataset")
+
 from .hf import submit_to_hf
 
 __all__ = ["submit_to_hf"]

src/lerobot/jobs/dataset.py

@@ -23,8 +23,8 @@ from __future__ import annotations
 
 from typing import TYPE_CHECKING
 
+from lerobot.datasets import LeRobotDataset
 from lerobot.utils.constants import HF_LEROBOT_HOME
-from lerobot.utils.import_utils import require_package
 
 if TYPE_CHECKING:
     from huggingface_hub import HfApi
@@ -49,9 +49,5 @@ def ensure_dataset_available(repo_id: str, *, api: HfApi, tags: list[str] | None
         )
 
     print(f"[dataset] '{repo_id}' is local-only; pushing to a PRIVATE Hub repo...")
-    # Lazy import: LeRobotDataset pulls in heavy dataset deps; defer until actually needed.
-    require_package("datasets", extra="dataset")
-    from lerobot.datasets import LeRobotDataset
-
     LeRobotDataset(repo_id).push_to_hub(private=True, tags=tags)
     print(f"[dataset] '{repo_id}' uploaded (private). The job will download it by repo_id.")

tests/jobs/test_dataset.py

@@ -12,7 +12,6 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
-import sys
 from unittest.mock import MagicMock
 
 import pytest
@@ -47,11 +46,7 @@ def test_dataset_local_only_uploads_privately(tmp_path, monkeypatch):
 
     api = _api_with_dataset(False)
     mock_ds_cls = MagicMock()
-    fake_datasets_module = MagicMock()
-    fake_datasets_module.LeRobotDataset = mock_ds_cls
-    monkeypatch.setitem(sys.modules, "lerobot.datasets", fake_datasets_module)
-    # The `datasets` extra isn't installed in the base test env; skip the import guard.
-    monkeypatch.setattr("lerobot.jobs.dataset.require_package", lambda *a, **k: None)
+    monkeypatch.setattr("lerobot.jobs.dataset.LeRobotDataset", mock_ds_cls)
 
     assert ensure_dataset_available("user/ds", api=api, tags=["lerobot", "lelab"]) is None