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/editor/headers.py

@@ -8,7 +8,7 @@ import logging
 import re
 from typing import Dict, List, Optional
 
-from cv_ocr_engines import _text_has_garbled_ipa
+from ocr.engines.engines import _text_has_garbled_ipa
 
 logger = logging.getLogger(__name__)
 
@@ -394,7 +394,7 @@ def _detect_colspan_cells(
     if len(columns) < 2 or not zone_words or not rows:
         return cells
 
-    from cv_words_first import _assign_word_to_row
+    from ocr.words_first import _assign_word_to_row
 
     # Column boundaries (midpoints between adjacent columns)
     col_boundaries = []