Version 1.9
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- Fixed the ``to`` method of ``FlowGraph`` to not change the underlying data, but the graph itself.
- Updated the reward calculation in ``BaseEnvironment`` to handle rewards defined over both latent spaces and postprocessed samples.
- Corrected the aggregation method in ``Epsilon``, ``Score``, and ``Velocity`` environments to use "sum" instead of the default aggregation.
- Improved the reduction logic in ``FlowGraph`` to properly compute ``reduction="mean"``.
