[split-required] Split final 43 files (500-668 LOC) to complete refactoring

klausur-service (11 files):
- cv_gutter_repair, ocr_pipeline_regression, upload_api
- ocr_pipeline_sessions, smart_spell, nru_worksheet_generator
- ocr_pipeline_overlays, mail/aggregator, zeugnis_api
- cv_syllable_detect, self_rag

backend-lehrer (17 files):
- classroom_engine/suggestions, generators/quiz_generator
- worksheets_api, llm_gateway/comparison, state_engine_api
- classroom/models (→ 4 submodules), services/file_processor
- alerts_agent/api/wizard+digests+routes, content_generators/pdf
- classroom/routes/sessions, llm_gateway/inference
- classroom_engine/analytics, auth/keycloak_auth
- alerts_agent/processing/rule_engine, ai_processor/print_versions

agent-core (5 files):
- brain/memory_store, brain/knowledge_graph, brain/context_manager
- orchestrator/supervisor, sessions/session_manager

admin-lehrer (5 components):
- GridOverlay, StepGridReview, DevOpsPipelineSidebar
- DataFlowDiagram, sbom/wizard/page

website (2 files):
- DependencyMap, lehrer/abitur-archiv

Other: nibis_ingestion, grid_detection_service, export-doclayout-onnx

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

klausur-service/backend/services/grid_detection_models.py

@@ -0,0 +1,164 @@
+"""
+Grid Detection Models v4
+
+Data classes for OCR grid detection results.
+Coordinates use percentage (0-100) and mm (A4 format).
+"""
+
+from enum import Enum
+from dataclasses import dataclass, field
+from typing import List, Dict, Any
+
+# A4 dimensions
+A4_WIDTH_MM = 210.0
+A4_HEIGHT_MM = 297.0
+
+# Column margin (1mm)
+COLUMN_MARGIN_MM = 1.0
+COLUMN_MARGIN_PCT = (COLUMN_MARGIN_MM / A4_WIDTH_MM) * 100
+
+
+class CellStatus(str, Enum):
+    EMPTY = "empty"
+    RECOGNIZED = "recognized"
+    PROBLEMATIC = "problematic"
+    MANUAL = "manual"
+
+
+class ColumnType(str, Enum):
+    ENGLISH = "english"
+    GERMAN = "german"
+    EXAMPLE = "example"
+    UNKNOWN = "unknown"
+
+
+@dataclass
+class OCRRegion:
+    """A word/phrase detected by OCR with bounding box coordinates in percentage (0-100)."""
+    text: str
+    confidence: float
+    x: float       # X position as percentage of page width
+    y: float       # Y position as percentage of page height
+    width: float   # Width as percentage of page width
+    height: float  # Height as percentage of page height
+
+    @property
+    def x_mm(self) -> float:
+        return round(self.x / 100 * A4_WIDTH_MM, 1)
+
+    @property
+    def y_mm(self) -> float:
+        return round(self.y / 100 * A4_HEIGHT_MM, 1)
+
+    @property
+    def width_mm(self) -> float:
+        return round(self.width / 100 * A4_WIDTH_MM, 1)
+
+    @property
+    def height_mm(self) -> float:
+        return round(self.height / 100 * A4_HEIGHT_MM, 2)
+
+    @property
+    def center_x(self) -> float:
+        return self.x + self.width / 2
+
+    @property
+    def center_y(self) -> float:
+        return self.y + self.height / 2
+
+    @property
+    def right(self) -> float:
+        return self.x + self.width
+
+    @property
+    def bottom(self) -> float:
+        return self.y + self.height
+
+
+@dataclass
+class GridCell:
+    """A cell in the detected grid with coordinates in percentage (0-100)."""
+    row: int
+    col: int
+    x: float
+    y: float
+    width: float
+    height: float
+    text: str = ""
+    confidence: float = 0.0
+    status: CellStatus = CellStatus.EMPTY
+    column_type: ColumnType = ColumnType.UNKNOWN
+    logical_row: int = 0
+    logical_col: int = 0
+    is_continuation: bool = False
+
+    @property
+    def x_mm(self) -> float:
+        return round(self.x / 100 * A4_WIDTH_MM, 1)
+
+    @property
+    def y_mm(self) -> float:
+        return round(self.y / 100 * A4_HEIGHT_MM, 1)
+
+    @property
+    def width_mm(self) -> float:
+        return round(self.width / 100 * A4_WIDTH_MM, 1)
+
+    @property
+    def height_mm(self) -> float:
+        return round(self.height / 100 * A4_HEIGHT_MM, 2)
+
+    def to_dict(self) -> dict:
+        return {
+            "row": self.row,
+            "col": self.col,
+            "x": round(self.x, 2),
+            "y": round(self.y, 2),
+            "width": round(self.width, 2),
+            "height": round(self.height, 2),
+            "x_mm": self.x_mm,
+            "y_mm": self.y_mm,
+            "width_mm": self.width_mm,
+            "height_mm": self.height_mm,
+            "text": self.text,
+            "confidence": self.confidence,
+            "status": self.status.value,
+            "column_type": self.column_type.value,
+            "logical_row": self.logical_row,
+            "logical_col": self.logical_col,
+            "is_continuation": self.is_continuation,
+        }
+
+
+@dataclass
+class GridResult:
+    """Result of grid detection."""
+    rows: int = 0
+    columns: int = 0
+    cells: List[List[GridCell]] = field(default_factory=list)
+    column_types: List[str] = field(default_factory=list)
+    column_boundaries: List[float] = field(default_factory=list)
+    row_boundaries: List[float] = field(default_factory=list)
+    deskew_angle: float = 0.0
+    stats: Dict[str, Any] = field(default_factory=dict)
+
+    def to_dict(self) -> dict:
+        cells_dicts = []
+        for row_cells in self.cells:
+            cells_dicts.append([c.to_dict() for c in row_cells])
+
+        return {
+            "rows": self.rows,
+            "columns": self.columns,
+            "cells": cells_dicts,
+            "column_types": self.column_types,
+            "column_boundaries": [round(b, 2) for b in self.column_boundaries],
+            "row_boundaries": [round(b, 2) for b in self.row_boundaries],
+            "deskew_angle": round(self.deskew_angle, 2),
+            "stats": self.stats,
+            "page_dimensions": {
+                "width_mm": A4_WIDTH_MM,
+                "height_mm": A4_HEIGHT_MM,
+                "format": "A4",
+            },
+        }