[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>

agent-core/brain/knowledge_models.py

@@ -0,0 +1,104 @@
+"""
+Knowledge Graph Models for Breakpilot Agents
+
+Entity and relationship data classes, plus type enumerations.
+"""
+
+from typing import Dict, Any
+from dataclasses import dataclass, field
+from datetime import datetime, timezone
+from enum import Enum
+
+
+class EntityType(Enum):
+    """Types of entities in the knowledge graph"""
+    STUDENT = "student"
+    TEACHER = "teacher"
+    CLASS = "class"
+    SUBJECT = "subject"
+    ASSIGNMENT = "assignment"
+    EXAM = "exam"
+    TOPIC = "topic"
+    CONCEPT = "concept"
+    RESOURCE = "resource"
+    CUSTOM = "custom"
+
+
+class RelationshipType(Enum):
+    """Types of relationships between entities"""
+    BELONGS_TO = "belongs_to"        # Student belongs to class
+    TEACHES = "teaches"              # Teacher teaches subject
+    ASSIGNED_TO = "assigned_to"      # Assignment assigned to student
+    COVERS = "covers"                # Exam covers topic
+    REQUIRES = "requires"            # Topic requires concept
+    RELATED_TO = "related_to"        # General relationship
+    PARENT_OF = "parent_of"          # Hierarchical relationship
+    CREATED_BY = "created_by"        # Creator relationship
+    GRADED_BY = "graded_by"          # Grading relationship
+
+
+@dataclass
+class Entity:
+    """Represents an entity in the knowledge graph"""
+    id: str
+    entity_type: EntityType
+    name: str
+    properties: Dict[str, Any] = field(default_factory=dict)
+    created_at: datetime = field(default_factory=lambda: datetime.now(timezone.utc))
+    updated_at: datetime = field(default_factory=lambda: datetime.now(timezone.utc))
+
+    def to_dict(self) -> Dict[str, Any]:
+        return {
+            "id": self.id,
+            "entity_type": self.entity_type.value,
+            "name": self.name,
+            "properties": self.properties,
+            "created_at": self.created_at.isoformat(),
+            "updated_at": self.updated_at.isoformat()
+        }
+
+    @classmethod
+    def from_dict(cls, data: Dict[str, Any]) -> "Entity":
+        return cls(
+            id=data["id"],
+            entity_type=EntityType(data["entity_type"]),
+            name=data["name"],
+            properties=data.get("properties", {}),
+            created_at=datetime.fromisoformat(data["created_at"]),
+            updated_at=datetime.fromisoformat(data["updated_at"])
+        )
+
+
+@dataclass
+class Relationship:
+    """Represents a relationship between two entities"""
+    id: str
+    source_id: str
+    target_id: str
+    relationship_type: RelationshipType
+    properties: Dict[str, Any] = field(default_factory=dict)
+    weight: float = 1.0
+    created_at: datetime = field(default_factory=lambda: datetime.now(timezone.utc))
+
+    def to_dict(self) -> Dict[str, Any]:
+        return {
+            "id": self.id,
+            "source_id": self.source_id,
+            "target_id": self.target_id,
+            "relationship_type": self.relationship_type.value,
+            "properties": self.properties,
+            "weight": self.weight,
+            "created_at": self.created_at.isoformat()
+        }
+
+    @classmethod
+    def from_dict(cls, data: Dict[str, Any]) -> "Relationship":
+        return cls(
+            id=data["id"],
+            source_id=data["source_id"],
+            target_id=data["target_id"],
+            relationship_type=RelationshipType(data["relationship_type"]),
+            properties=data.get("properties", {}),
+            weight=data.get("weight", 1.0),
+            created_at=datetime.fromisoformat(data["created_at"])
+        )