Add Wall-X serving and Turtle2 TCP WebSocket bridge

wall_x/data/backends/lerobot/loader.py

@@ -9,6 +9,7 @@ from typing import Protocol, SupportsIndex, TypeVar
 import numpy as np
 import torch
 from lerobot.datasets.lerobot_dataset import LeRobotDataset, LeRobotDatasetMetadata
+from lerobot.datasets.utils import check_delta_timestamps, get_delta_indices
 from qwen_vl_utils.vision_process import smart_resize
 from torch.utils.data import DistributedSampler, random_split
 from transformers import AutoProcessor
@@ -788,6 +789,27 @@ def load_lerobot_data(
                 video_backend="pyav",
             )
 
+            # Some locally patched LeRobot releases return from timestamp
+            # validation before initializing delta_indices. Restore the normal
+            # upstream behavior so action chunks contain the requested horizon.
+            if (
+                train_dataset.delta_timestamps is not None
+                and train_dataset.delta_indices is None
+            ):
+                check_delta_timestamps(
+                    train_dataset.delta_timestamps,
+                    train_dataset.fps,
+                    train_dataset.tolerance_s,
+                )
+                train_dataset.delta_indices = get_delta_indices(
+                    train_dataset.delta_timestamps, train_dataset.fps
+                )
+                logger.warning(
+                    "[Global rank %s] LeRobot did not initialize delta_indices; "
+                    "restored them in Wall-X for action chunk loading",
+                    global_rank,
+                )
+
             logger.info(
                 "[Global rank %s] Finished loading on local_rank=%s",
                 global_rank,