feat(envs): add RoboCasa365 benchmark integration

Add RoboCasa365 (arXiv:2603.04356) as a new simulation benchmark with
365 everyday kitchen manipulation tasks across 2,500 diverse environments.

New files:
- src/lerobot/envs/robocasa.py: gym.Env wrapper with deferred env creation,
  flat 12D action / 16D state vectors, 3-camera support
- docs/source/robocasa.mdx: user-facing documentation
- docker/Dockerfile.benchmark.robocasa: CI benchmark image

Modified files:
- src/lerobot/envs/configs.py: RoboCasaEnv config (--env.type=robocasa)
- pyproject.toml: robocasa optional dependency group
- docs/source/_toctree.yml: sidebar entry
- .github/workflows/benchmark_tests.yml: integration test job

Refs: https://arxiv.org/abs/2603.04356, https://robocasa.ai
Related: huggingface/lerobot#321

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

docker/Dockerfile.benchmark.robocasa

@@ -0,0 +1,36 @@
+# Copyright 2025 The HuggingFace Inc. team. All rights reserved.
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+# Benchmark image for RoboCasa365 integration tests.
+# Extends the nightly GPU image (which already has all extras installed)
+# with the PR's source code and RoboCasa-specific asset setup.
+#
+# Build:  docker build -f docker/Dockerfile.benchmark.robocasa -t lerobot-benchmark-robocasa .
+# Run:    docker run --gpus all --rm lerobot-benchmark-robocasa lerobot-eval ...
+
+FROM huggingface/lerobot-gpu:latest
+
+# Install robocasa and its dependencies
+RUN pip install --no-cache-dir \
+    "robocasa @ git+https://github.com/robocasa/robocasa.git@v1.0.0" \
+    "robosuite @ git+https://github.com/ARISE-Initiative/robosuite.git"
+
+# Set up robocasa macros and download kitchen assets
+RUN python -m robocasa.scripts.setup_macros && \
+    python -m robocasa.scripts.download_kitchen_assets
+
+# Overlay the PR's source code on top of the nightly image.
+COPY --chown=user_lerobot:user_lerobot . .
+
+CMD ["/bin/bash"]