Restructure: Move 47 cv_* files into ocr/ package

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

klausur-service/backend/ocr/preprocessing/__init__.py

@@ -0,0 +1,2 @@
+"""Preprocessing sub-package (deskew, dewarp, image I/O)."""
+from .preprocessing import *  # noqa: F401,F403

klausur-service/backend/ocr/preprocessing/deskew.py

@@ -11,7 +11,7 @@ from typing import Any, Dict, Tuple
 
 import numpy as np
 
-from cv_vocab_types import (
+from ..types import (
     CV2_AVAILABLE,
     TESSERACT_AVAILABLE,
 )

klausur-service/backend/ocr/preprocessing/dewarp.py

@@ -16,7 +16,7 @@ from typing import Any, Dict, List, Tuple
 
 import numpy as np
 
-from cv_vocab_types import (
+from ..types import (
     CV2_AVAILABLE,
     TESSERACT_AVAILABLE,
 )

klausur-service/backend/ocr/preprocessing/preprocessing.py

@@ -17,7 +17,7 @@ from typing import Tuple
 
 import numpy as np
 
-from cv_vocab_types import (
+from ..types import (
     CV2_AVAILABLE,
     TESSERACT_AVAILABLE,
 )
@@ -38,7 +38,7 @@ except ImportError:
     Image = None  # type: ignore[assignment,misc]
 
 # Re-export all deskew functions
-from cv_preprocessing_deskew import (  # noqa: F401
+from .deskew import (  # noqa: F401
     deskew_image,
     deskew_image_by_word_alignment,
     deskew_image_iterative,
@@ -48,7 +48,7 @@ from cv_preprocessing_deskew import (  # noqa: F401
 )
 
 # Re-export all dewarp functions
-from cv_preprocessing_dewarp import (  # noqa: F401
+from .dewarp import (  # noqa: F401
     _apply_shear,
     _detect_shear_angle,
     _detect_shear_by_hough,