feat: add benchmark orchestration, LIBERO-plus install parity, and eval hardening

- Add lerobot-benchmark CLI for multi-benchmark train/eval workflows
- Add benchmark_training.mdx documentation
- Add libero-plus pip extra alias with EGL probe deps matching standard libero
- Harden libero.py: wand mock, init-state fallback, renderer EGL→OSMesa fallback
- Add multimodal_analysis.py script and SLURM training template

Made-with: Cursor

docs/source/_toctree.yml

@@ -19,6 +19,8 @@
     title: Multi GPU training
   - local: peft_training
     title: Training with PEFT (e.g., LoRA)
+  - local: benchmark_training
+    title: Benchmark Training & Evaluation
   title: "Tutorials"
 - sections:
   - local: lerobot-dataset-v3