chore: import upstream snapshot with attribution

skillopt/engine/__init__.py

@@ -0,0 +1,9 @@
+"""ReflACT Engine -- the training runner.
+
+Analogous to the Runner in mmengine: orchestrates the full training pipeline
+including rollout, gradient computation, aggregation, optimization, and
+evaluation.
+"""
+from skillopt.engine.trainer import ReflACTTrainer  # noqa: F401
+
+__all__ = ["ReflACTTrainer"]