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/geometry.py

@@ -0,0 +1,27 @@
+"""
+OCR Pipeline Geometry API (barrel re-export)
+
+This module was split into:
+  - ocr_pipeline_deskew.py     (Deskew endpoints)
+  - ocr_pipeline_dewarp.py     (Dewarp endpoints)
+  - ocr_pipeline_structure.py  (Structure detection + exclude regions)
+  - ocr_pipeline_columns.py    (Column detection + ground truth)
+
+The `router` object is assembled here by including all sub-routers.
+Importers that did `from ocr_pipeline_geometry import router` continue to work.
+"""
+
+from fastapi import APIRouter
+
+from .deskew import router as _deskew_router
+from .dewarp import router as _dewarp_router
+from .structure import router as _structure_router
+from .columns import router as _columns_router
+
+# Assemble the combined router.
+# All sub-routers use prefix="/api/v1/ocr-pipeline", so include without extra prefix.
+router = APIRouter()
+router.include_router(_deskew_router)
+router.include_router(_dewarp_router)
+router.include_router(_structure_router)
+router.include_router(_columns_router)