feat: Netzwerkanalyse-Feature (Wissensgraph)

Neues Feature zur Visualisierung von Entitäten und Beziehungen
aus ausgewählten Lagen als interaktiver d3.js-Netzwerkgraph.

- Haiku extrahiert Entitäten (Person, Organisation, Ort, Ereignis, Militär)
- Opus analysiert Beziehungen und korrigiert Haiku-Fehler
- 6 neue DB-Tabellen (network_analyses, _entities, _relations, etc.)
- REST-API: CRUD + Generierung + Export (JSON/CSV)
- d3.js Force-Directed Graph mit Zoom, Filter, Suche, Export
- WebSocket-Events für Live-Progress während Generierung
- Sidebar-Integration mit Netzwerkanalysen-Sektion

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

src/models_network.py

@@ -0,0 +1,59 @@
+"""Pydantic Models für Netzwerkanalyse Request/Response Schemas."""
+from pydantic import BaseModel, Field
+from typing import Optional
+
+
+class NetworkAnalysisCreate(BaseModel):
+    name: str = Field(min_length=1, max_length=200)
+    incident_ids: list[int] = Field(min_length=1)
+
+
+class NetworkAnalysisUpdate(BaseModel):
+    name: Optional[str] = Field(default=None, max_length=200)
+    incident_ids: Optional[list[int]] = None
+
+
+class NetworkEntityResponse(BaseModel):
+    id: int
+    name: str
+    name_normalized: str
+    entity_type: str
+    description: str = ""
+    aliases: list[str] = []
+    mention_count: int = 0
+    corrected_by_opus: bool = False
+    metadata: dict = {}
+
+
+class NetworkRelationResponse(BaseModel):
+    id: int
+    source_entity_id: int
+    target_entity_id: int
+    category: str
+    label: str
+    description: str = ""
+    weight: int = 1
+    status: str = ""
+    evidence: list[str] = []
+
+
+class NetworkAnalysisResponse(BaseModel):
+    id: int
+    name: str
+    status: str
+    entity_count: int = 0
+    relation_count: int = 0
+    has_update: bool = False
+    incident_ids: list[int] = []
+    incident_titles: list[str] = []
+    data_hash: Optional[str] = None
+    last_generated_at: Optional[str] = None
+    created_by: int = 0
+    created_by_username: str = ""
+    created_at: str = ""
+
+
+class NetworkGraphResponse(BaseModel):
+    analysis: NetworkAnalysisResponse
+    entities: list[NetworkEntityResponse] = []
+    relations: list[NetworkRelationResponse] = []