When --job.target names a GPU flavor, train() dispatches to lerobot.jobs.submit_to_hf
instead of training locally: it authenticates, ensures the dataset is on the Hub
(pushing a local-only one privately), serializes a pod-compatible train_config.json
(strips client-only fields, points at the model repo), submits via HfApi.run_job
with HF_TOKEN/WANDB_API_KEY secrets, then streams logs and finishes when the model
is pushed. Wires push_checkpoint_to_hub into the training loop behind
save_checkpoint_to_hub, and tags jobs/datasets/model with 'lerobot' + --job.tags.