refactor: 按go modules规范重构

backend/internal/service/interface.go

@@ -0,0 +1,20 @@
+package service
+
+import "knowledge-graph-backend/internal/model"
+
+type GraphService interface {
+	GetGraphData() model.GraphData
+	GetSimpleGraphData() model.SimpleGraphData
+	GetNodeByID(id string) (model.Node, bool)
+	SearchNodes(query string) []model.Node
+	GetNeighbors(nodeID string) (model.NeighborResponse, bool)
+	GetStats() map[string]int
+
+	// 新增增删改接口
+	CreateNode(req model.CreateNodeRequest) (model.Node, error)
+	UpdateNode(id string, req model.UpdateNodeRequest) (model.Node, error)
+	DeleteNode(id string) error
+
+	CreateEdge(req model.CreateEdgeRequest) (model.Edge, error)
+	DeleteEdge(id string) error
+}