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/ocr/spell/core.py

@@ -159,7 +159,7 @@ class _SmartSpellCoreBase:
             return True
         # Also accept known abbreviations (sth, sb, adj, etc.)
         try:
-            from cv_ocr_engines import _KNOWN_ABBREVIATIONS
+            from ocr.engines.engines import _KNOWN_ABBREVIATIONS
             if w in _KNOWN_ABBREVIATIONS:
                 return True
         except ImportError:

klausur-service/backend/ocr/spell/text.py

@@ -35,7 +35,7 @@ class SmartSpellChecker(_SmartSpellCoreBase):
         """
         # Import known abbreviations for vocabulary context
         try:
-            from cv_ocr_engines import _KNOWN_ABBREVIATIONS
+            from ocr.engines.engines import _KNOWN_ABBREVIATIONS
         except ImportError:
             _KNOWN_ABBREVIATIONS = set()
 
@@ -149,7 +149,7 @@ class SmartSpellChecker(_SmartSpellCoreBase):
         # --- Pass 1: Boundary repair between adjacent unknown words ---
         # Import abbreviations for the heuristic below
         try:
-            from cv_ocr_engines import _KNOWN_ABBREVIATIONS as _ABBREVS
+            from ocr.engines.engines import _KNOWN_ABBREVIATIONS as _ABBREVS
         except ImportError:
             _ABBREVS = set()