Update changelog for alpha.1 release; fix linting

Author: RalfG

CHANGELOG.md

@@ -6,14 +6,15 @@ The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/),
 and this project adheres to
 [Semantic Versioning](https://semver.org/spec/v2.0.0.html).
 
-## Unreleased
+## [4.0.0-alpha.1]
 
 ### Changed
 
 - Simplified the public package API by splitting up the single class-based API into core functions (`predict`, `finetune`, `train`, etc.)
 - Switched deep learning framework from Tensorflow to PyTorch
 - Speed up predictions by removing ensemble method where output from three models with differing kernel sizes was averaged to one prediction
 - Separated calibration logic to dedicated reusable module with sklearn-like API.
+- Improved computational efficiency of piece-wise linear calibration and set sensible default parameters
 - Built-in transfer learning functionality, instead of using external `deeplcretrainer` package.
 - Cleaned up package, removing legacy and unused code and files, and improving modularity
 - Modernized CI workflows to use `uv`

deeplc/core.py

@@ -13,7 +13,6 @@
 from deeplc import _model_ops
 from deeplc.calibration import (
     Calibration,
-    PiecewiseLinearCalibration,
     SplineTransformerCalibration,
 )
 from deeplc.data import DeepLCDataset, split_datasets