Fix: Resolve all lint errors from ocr/ restructure

- Added ocr_region import to cell_grid/build.py and legacy.py
- Fixed circular import in engines.py via lazy import
- Auto-fixed 22 unused imports via ruff --fix

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

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

@@ -16,20 +16,14 @@ Lizenz: Apache 2.0 (kommerziell nutzbar)
 DATENSCHUTZ: Alle Verarbeitung erfolgt lokal.
 """
 
-import io
 import logging
 import os
-import re
-from typing import Any, Dict, List, Optional, Tuple
+from typing import Any, Dict, List, Optional
 
 import numpy as np
 
 from ..types import (
-    IPA_AVAILABLE,
     PageRegion,
-    RowGeometry,
-    _britfone_dict,
-    _ipa_convert_american,
 )
 
 logger = logging.getLogger(__name__)
@@ -194,7 +188,7 @@ def ocr_region_trocr(img_bgr: np.ndarray, region: PageRegion, handwritten: bool
         if region.height > 0 and region.width > 0:
             ocr_img_crop = cv2.cvtColor(img_bgr, cv2.COLOR_BGR2GRAY) if img_bgr is not None else None
             if ocr_img_crop is not None:
-                return ocr_region(ocr_img_crop, region, lang="eng+deu", psm=6)
+                from ..review.pipeline import ocr_region as _ocr_region; return _ocr_region(ocr_img_crop, region, lang="eng+deu", psm=6)
         return []
 
     crop = img_bgr[region.y:region.y + region.height, region.x:region.x + region.width]
@@ -209,7 +203,7 @@ def ocr_region_trocr(img_bgr: np.ndarray, region: PageRegion, handwritten: bool
         if processor is None or model is None:
             logger.warning("TrOCR model not loaded, falling back to Tesseract")
             ocr_img_crop = cv2.cvtColor(img_bgr, cv2.COLOR_BGR2GRAY)
-            return ocr_region(ocr_img_crop, region, lang="eng+deu", psm=6)
+            from ..review.pipeline import ocr_region as _ocr_region; return _ocr_region(ocr_img_crop, region, lang="eng+deu", psm=6)
 
         pil_crop = _PILImage.fromarray(cv2.cvtColor(crop, cv2.COLOR_BGR2RGB))
         lines = _split_into_lines(pil_crop)
@@ -260,14 +254,13 @@ def ocr_region_lighton(img_bgr: np.ndarray, region: PageRegion) -> List[Dict[str
         if RAPIDOCR_AVAILABLE and img_bgr is not None:
             return ocr_region_rapid(img_bgr, region)
         ocr_img_crop = cv2.cvtColor(img_bgr, cv2.COLOR_BGR2GRAY) if img_bgr is not None else None
-        return ocr_region(ocr_img_crop, region, lang="eng+deu", psm=6) if ocr_img_crop is not None else []
+        from ..review.pipeline import ocr_region as _ocr_region; return _ocr_region(ocr_img_crop, region, lang="eng+deu", psm=6) if ocr_img_crop is not None else []
 
     crop = img_bgr[region.y:region.y + region.height, region.x:region.x + region.width]
     if crop.size == 0:
         return []
 
     try:
-        import io
         import torch
         from PIL import Image as _PILImage
 
@@ -277,7 +270,7 @@ def ocr_region_lighton(img_bgr: np.ndarray, region: PageRegion) -> List[Dict[str
             if RAPIDOCR_AVAILABLE and img_bgr is not None:
                 return ocr_region_rapid(img_bgr, region)
             ocr_img_crop = cv2.cvtColor(img_bgr, cv2.COLOR_BGR2GRAY)
-            return ocr_region(ocr_img_crop, region, lang="eng+deu", psm=6)
+            from ..review.pipeline import ocr_region as _ocr_region; return _ocr_region(ocr_img_crop, region, lang="eng+deu", psm=6)
 
         pil_crop = _PILImage.fromarray(cv2.cvtColor(crop, cv2.COLOR_BGR2RGB))
         conversation = [{"role": "user", "content": [{"type": "image"}]}]

klausur-service/backend/ocr/engines/ipa_repair.py

@@ -14,7 +14,7 @@ Contains:
 
 import logging
 import re
-from typing import Any, Dict, List, Optional
+from typing import List
 
 from ..types import IPA_AVAILABLE
 from .ipa_lookup import (