Restructure: Move 47 cv_* files into ocr/ package

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

klausur-service/backend/ocr/layout/analyze.py

@@ -13,8 +13,8 @@ from typing import List
 
 import numpy as np
 
-from cv_vocab_types import PageRegion
-from cv_layout_detection import _find_content_bounds
+from ..types import PageRegion
+from .detection import _find_content_bounds
 
 logger = logging.getLogger(__name__)
 
@@ -246,7 +246,7 @@ def analyze_layout(layout_img: np.ndarray, ocr_img: np.ndarray) -> List[PageRegi
 
     # Add header/footer info (gap-based detection with fallback)
     # Lazy import to avoid circular dependency with cv_layout.py
-    from cv_layout_detection import _add_header_footer
+    from .detection import _add_header_footer
     _add_header_footer(regions, top_y, bottom_y, w, h, inv=inv)
 
     top_region = next((r.type for r in regions if r.type in ('header', 'margin_top')), 'none')