Remove webshop_goals_train.json / webshop_goals_val.json (task_id-indexed goals). Add webshop_{train,val,heldout}_verl_agent_small.json: self-contained goals (goal_json, prices_json) replayed from verl-agent's environment draws, for the webshop-simulator-env:small image; the held-out set's products never appear in training.
