[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>

backend-lehrer/generators/quiz_models.py

@@ -0,0 +1,65 @@
+"""
+Quiz Models - Datenmodelle fuer Quiz-Generierung.
+
+Enthaelt alle Dataclasses und Enums fuer Quiz-Typen:
+- True/False Fragen
+- Zuordnungsaufgaben (Matching)
+- Sortieraufgaben
+- Offene Fragen
+"""
+
+from typing import List, Any, Optional
+from dataclasses import dataclass
+from enum import Enum
+
+
+class QuizType(str, Enum):
+    """Typen von Quiz-Aufgaben."""
+    TRUE_FALSE = "true_false"
+    MATCHING = "matching"
+    SORTING = "sorting"
+    OPEN_ENDED = "open_ended"
+
+
+@dataclass
+class TrueFalseQuestion:
+    """Eine Wahr/Falsch-Frage."""
+    statement: str
+    is_true: bool
+    explanation: str
+    source_reference: Optional[str] = None
+
+
+@dataclass
+class MatchingPair:
+    """Ein Zuordnungspaar."""
+    left: str
+    right: str
+    hint: Optional[str] = None
+
+
+@dataclass
+class SortingItem:
+    """Ein Element zum Sortieren."""
+    text: str
+    correct_position: int
+    category: Optional[str] = None
+
+
+@dataclass
+class OpenQuestion:
+    """Eine offene Frage."""
+    question: str
+    model_answer: str
+    keywords: List[str]
+    points: int = 1
+
+
+@dataclass
+class Quiz:
+    """Ein komplettes Quiz."""
+    quiz_type: QuizType
+    title: str
+    questions: List[Any]  # Je nach Typ unterschiedlich
+    topic: Optional[str] = None
+    difficulty: str = "medium"