Restructure: Move 47 cv_* files into ocr/ package

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

klausur-service/backend/ocr/review/pipeline.py

@@ -13,24 +13,24 @@ from typing import Any, Dict, List, Optional
 
 import numpy as np
 
-from cv_vocab_types import (
+from ..types import (
     CV_PIPELINE_AVAILABLE,
     PageRegion,
     PipelineResult,
     VocabRow,
 )
-from cv_preprocessing import (
+from ..preprocessing.preprocessing import (
     deskew_image,
     dewarp_image,
     render_image_high_res,
     render_pdf_high_res,
 )
-from cv_layout import (
+from ..layout.layout import (
     analyze_layout,
     create_layout_image,
     create_ocr_image,
 )
-from cv_ocr_engines import (
+from ..engines.engines import (
     _group_words_into_lines,
 )