Restructure: Move 47 cv_* files into ocr/ package

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

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

@@ -16,7 +16,7 @@ DATENSCHUTZ: Alle Verarbeitung erfolgt lokal.
 """
 
 # --- Helpers ---
-from cv_cell_grid_helpers import (  # noqa: F401
+from .helpers import (  # noqa: F401
     _MIN_WORD_CONF,
     _compute_cell_padding,
     _ensure_minimum_crop_size,
@@ -26,26 +26,26 @@ from cv_cell_grid_helpers import (  # noqa: F401
 )
 
 # --- v2 build (current default) ---
-from cv_cell_grid_build import (  # noqa: F401
+from .build import (  # noqa: F401
     _NARROW_COL_THRESHOLD_PCT,
     _ocr_cell_crop,
     build_cell_grid_v2,
 )
 
 # --- Legacy build (DEPRECATED) ---
-from cv_cell_grid_legacy import (  # noqa: F401
+from .legacy import (  # noqa: F401
     _ocr_single_cell,
     build_cell_grid,
 )
 
 # --- Streaming variants ---
-from cv_cell_grid_streaming import (  # noqa: F401
+from .streaming import (  # noqa: F401
     build_cell_grid_streaming,
     build_cell_grid_v2_streaming,
 )
 
 # --- Row merging ---
-from cv_cell_grid_merge import (  # noqa: F401
+from .merge import (  # noqa: F401
     _PHONETIC_ONLY_RE,
     _is_phonetic_only_text,
     _merge_continuation_rows,
@@ -54,7 +54,7 @@ from cv_cell_grid_merge import (  # noqa: F401
 )
 
 # --- Vocab extraction ---
-from cv_cell_grid_vocab import (  # noqa: F401
+from .vocab import (  # noqa: F401
     _cells_to_vocab_entries,
     build_word_grid,
 )