Reorganiza backend

backend/app/models.py

@@ -8,6 +8,9 @@ class Node(BaseModel):
     termType: str  # "uri" | "bnode"
     iri: str
     label: str | None = None
+    # Optional because /api/nodes (RDFStore) doesn't currently provide positions.
+    x: float | None = None
+    y: float | None = None
 
 
 class Edge(BaseModel):
@@ -36,8 +39,19 @@ class EdgesResponse(BaseModel):
 
 
 class GraphResponse(BaseModel):
+    class Meta(BaseModel):
+        backend: str
+        ttl_path: str | None = None
+        sparql_endpoint: str | None = None
+        include_bnodes: bool
+        node_limit: int
+        edge_limit: int
+        nodes: int
+        edges: int
+
     nodes: list[Node]
     edges: list[Edge]
+    meta: Meta | None = None
 
 
 class SparqlQueryRequest(BaseModel):