refactor(pipeline): feature contract now categorizes between OBS or Action (#1867)

* refactor(processor): signature of transform_features

* refactor(processor): remove prefixes + processor respect new transform_features signature + update test accordingly

* refactor(processor): rename now is only for visual

* refactor(processor): update normalize processor

* refactor(processor): update vanilla processor features

* refactor(processor): feature contract now uses its own enum

* chore(processor): rename renameprocessor

* chore(processor): minor changes

* refactor(processor): add create & change aggregate

* refactor(processor): update aggregate

* refactor(processor): simplify to functions, fix features contracts and rename function

* test(processor): remove to converter tests as now they are very simple

* chore(docs): recover docs joint observations processor

* fix(processor): update RKP

* fix(tests): recv diff test_pipeline

* chore(tests): add docs to test

* chore(processor): leave obs language constant untouched

* fix(processor): correct new shape of feature in crop image processor

tests/processor/test_smolvla_processor.py

@@ -20,7 +20,7 @@ from unittest.mock import patch
 import pytest
 import torch
 
-from lerobot.configs.types import FeatureType, NormalizationMode, PolicyFeature
+from lerobot.configs.types import FeatureType, NormalizationMode, PipelineFeatureType, PolicyFeature
 from lerobot.constants import ACTION, OBS_IMAGE, OBS_STATE
 from lerobot.policies.smolvla.configuration_smolvla import SmolVLAConfig
 from lerobot.policies.smolvla.processor_smolvla import (
@@ -33,7 +33,7 @@ from lerobot.processor import (
     EnvTransition,
     NormalizerProcessorStep,
     ProcessorStep,
-    RenameProcessorStep,
+    RenameObservationsProcessorStep,
     TransitionKey,
     UnnormalizerProcessorStep,
 )
@@ -122,7 +122,7 @@ def test_make_smolvla_processor_basic():
 
     # Check steps in preprocessor
     assert len(preprocessor.steps) == 6
-    assert isinstance(preprocessor.steps[0], RenameProcessorStep)
+    assert isinstance(preprocessor.steps[0], RenameObservationsProcessorStep)
     assert isinstance(preprocessor.steps[1], AddBatchDimensionProcessorStep)
     assert isinstance(preprocessor.steps[2], SmolVLANewLineProcessor)
     # Step 3 would be TokenizerProcessorStep but it's mocked
@@ -400,7 +400,7 @@ def test_smolvla_newline_processor_transform_features():
 
     # Test transform_features
     features = {
-        OBS_STATE: PolicyFeature(type=FeatureType.STATE, shape=(10,)),
+        PipelineFeatureType.OBSERVATION: {OBS_STATE: PolicyFeature(type=FeatureType.STATE, shape=(10,))},
     }
     result = processor.transform_features(features)
     assert result == features  # Should return unchanged