docs(jobs): document the model-pushed marker contract and orphaned repos

Follow-up to the claude[bot] review on #3856 (non-blocking observations):

- Cross-reference the "Model pushed to <url>" log line between its producer
  (PreTrainedPolicy.push_model_to_hub) and the remote-run consumer in
  submit_to_hf, noting the contract is an early-finish optimization that
  falls back to status polling if it drifts.
- Note in the HF Jobs guide that a failed remote run leaves its model repo
  on the Hub (it is not auto-deleted) and how to remove it.

docs/source/il_robots.mdx

@@ -626,6 +626,8 @@ Every job (and any dataset pushed by the run) is tagged `lerobot` so it's easy t
 
 By default the job runs until training finishes, with no time limit. Cap it with an HF Jobs duration string if you want a hard ceiling, e.g. `--job.timeout=4h`.
 
+> **Note:** the model repo is created up front (it holds the staged training config the job runs from). If a run fails before the model is pushed, that repo is left on the Hub so you can inspect it — it is not deleted automatically, so repeated failures can leave empty repos behind. Remove one with `hf repo delete <repo-id>`.
+
 **Prerequisites:** run `hf auth login` before submitting. For Weights & Biases integration, run `wandb login` or set `WANDB_API_KEY` on your machine — the key is forwarded to the job automatically.
 
 #### Upload policy checkpoints