Restructure: Move grid_* + vocab_* into packages (klausur-service)

grid/ package (16 files):
  grid/build/   — core, zones, cleanup, text_ops, cell_ops, finalize
  grid/editor/  — api, helpers, columns, filters, headers, zones

vocab/ package (10 files):
  vocab/worksheet/ — api, models, extraction, generation, ocr, upload, analysis, compare
  vocab/           — session_store, learn_bridge

26 backward-compat shims. Internal imports relative. RAG untouched.

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

klausur-service/backend/grid_editor_api_unified.py

@@ -1,71 +1,4 @@
-"""
-Grid Editor API — unified grid endpoints.
-"""
-
-import logging
-
-from fastapi import APIRouter, HTTPException
-
-from ocr_pipeline_session_store import (
-    get_session_db,
-    update_session_db,
-)
-
-logger = logging.getLogger(__name__)
-
-router = APIRouter(prefix="/api/v1/ocr-pipeline", tags=["grid-editor"])
-
-
-@router.post("/sessions/{session_id}/build-unified-grid")
-async def build_unified_grid_endpoint(session_id: str):
-    """Build a single-zone unified grid merging content + box zones.
-
-    Takes the existing multi-zone grid_editor_result and produces a
-    unified grid where boxes are integrated into the main row sequence.
-    Persists as unified_grid_result (preserves original multi-zone data).
-    """
-    session = await get_session_db(session_id)
-    if not session:
-        raise HTTPException(status_code=404, detail=f"Session {session_id} not found")
-
-    grid_data = session.get("grid_editor_result")
-    if not grid_data:
-        raise HTTPException(status_code=400, detail="No grid data. Run build-grid first.")
-
-    from unified_grid import build_unified_grid
-
-    result = build_unified_grid(
-        zones=grid_data.get("zones", []),
-        image_width=grid_data.get("image_width", 0),
-        image_height=grid_data.get("image_height", 0),
-        layout_metrics=grid_data.get("layout_metrics", {}),
-    )
-
-    # Persist as separate field (don't overwrite original multi-zone grid)
-    await update_session_db(session_id, unified_grid_result=result)
-
-    logger.info(
-        "build-unified-grid session %s: %d rows, %d cells",
-        session_id,
-        result.get("summary", {}).get("total_rows", 0),
-        result.get("summary", {}).get("total_cells", 0),
-    )
-
-    return result
-
-
-@router.get("/sessions/{session_id}/unified-grid")
-async def get_unified_grid(session_id: str):
-    """Retrieve the unified grid for a session."""
-    session = await get_session_db(session_id)
-    if not session:
-        raise HTTPException(status_code=404, detail=f"Session {session_id} not found")
-
-    result = session.get("unified_grid_result")
-    if not result:
-        raise HTTPException(
-            status_code=404,
-            detail="No unified grid. Run build-unified-grid first.",
-        )
-
-    return result
+# Backward-compat shim -- module moved to grid/editor/api_unified.py
+import importlib as _importlib
+import sys as _sys
+_sys.modules[__name__] = _importlib.import_module("grid.editor.api_unified")