- Rename 'done' to 'terminated' for true task completion
- Use 'truncated' for time-limit termination
- Change torch.empty to torch.zeros for storage initialization
- Convert _lerobotdataset_to_transitions to generator for memory efficiency
- Add proper docstrings to BatchTransition and ReplayBuffer
- Update concatenate_batch_transitions to use new terminology
- Update tests to use new field names
This aligns ReplayBuffer with Gymnasium's termination semantics where:
- terminated: Episode ended due to task success/failure
- truncated: Episode ended due to time limit or external factors
* chore: replace hard-coded 'action' values with constants throughout all the source code
* chore(tests): replace hard-coded action values with constants throughout all the test code
* chore: replace hard-coded OBS values with constants throughout all the source code
* chore(tests): replace hard-coded OBS values with constants throughout all the test code