实现代理节点功能，包括主程序入口、配置加载、心跳检测和状态管理，添加相关服务和API响应结构

atsf_agent/internal/state/state_test.go

@@ -0,0 +1,21 @@
+package state
+
+import (
+	"path/filepath"
+	"testing"
+)
+
+func TestEnsureNodeIDPersists(t *testing.T) {
+	store := NewStore(filepath.Join(t.TempDir(), "state.json"))
+	nodeID1, err := store.EnsureNodeID()
+	if err != nil {
+		t.Fatalf("EnsureNodeID failed: %v", err)
+	}
+	nodeID2, err := store.EnsureNodeID()
+	if err != nil {
+		t.Fatalf("EnsureNodeID second call failed: %v", err)
+	}
+	if nodeID1 == "" || nodeID1 != nodeID2 {
+		t.Fatal("expected node id to persist across calls")
+	}
+}