Restructure: Move ocr_pipeline + labeling + crop into ocr/ package

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

klausur-service/backend/ocr_pipeline_regression.py

@@ -1,22 +1,4 @@
-"""
-OCR Pipeline Regression Tests — barrel re-export.
-
-All implementation split into:
-  ocr_pipeline_regression_helpers   — DB persistence, snapshot, comparison
-  ocr_pipeline_regression_endpoints — FastAPI routes
-
-Lizenz: Apache 2.0
-DATENSCHUTZ: Alle Verarbeitung erfolgt lokal.
-"""
-
-# Helpers (used by grid_editor_api_grid.py)
-from ocr_pipeline_regression_helpers import (  # noqa: F401
-    _init_regression_table,
-    _persist_regression_run,
-    _extract_cells_for_comparison,
-    _build_reference_snapshot,
-    compare_grids,
-)
-
-# Endpoints (router used by ocr_pipeline_api.py)
-from ocr_pipeline_regression_endpoints import router  # noqa: F401
+# Backward-compat shim -- module moved to ocr/pipeline/regression.py
+import importlib as _importlib
+import sys as _sys
+_sys.modules[__name__] = _importlib.import_module("ocr.pipeline.regression")