Fix: Update all old-style imports inside packages to new paths

65 files in klausur-service packages + 3 in backend-lehrer packages
had stale imports referencing deleted shim modules.

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

klausur-service/backend/grid/build/zones.py

@@ -11,11 +11,11 @@ from typing import Any, Dict, List, Optional
 import cv2
 import numpy as np
 
-from cv_box_detect import detect_boxes, split_page_into_zones
-from cv_graphic_detect import detect_graphic_elements
-from cv_color_detect import recover_colored_text
-from cv_vocab_types import PageZone
-from ocr_pipeline_session_store import get_session_image
+from ocr.detect.box_detect import detect_boxes, split_page_into_zones
+from ocr.detect.graphic_detect import detect_graphic_elements
+from ocr.detect.color_detect import recover_colored_text
+from ocr.types import PageZone
+from ocr.pipeline.session_store import get_session_image
 
 from grid.editor.filters import (
     _filter_border_strip_words,