Return one quantile-regression LightGBM ForecasterRecursive per quantile.
Each forecaster uses LGBMRegressor(objective="quantile", alpha=q) and the same lag/rolling configuration as :func:default_lgbm_forecaster_factory, so a caller can fit the lower/median/upper heads independently and assemble a band with :func:predict_quantile_band. Deterministic given config.random_state; sf2-safe (LightGBM only, no torch/optuna). Refs hong16b, roma19a.
/home/runner/work/spotforecast2-safe/spotforecast2-safe/src/spotforecast2_safe/forecaster/base.py:476: FutureWarning: The `regressor` attribute is deprecated and will be removed in future versions. Use `estimator` instead.
warnings.warn(