Implement grpc server in the daemon to receive cluster requests

internal/machine/api/server.go

@@ -0,0 +1,20 @@
+package api
+
+import (
+	"context"
+	pb2 "uncloud/internal/machine/api/pb"
+)
+
+// Server is the gRPC server for the Cluster service.
+type Server struct {
+	pb2.UnimplementedClusterServer
+}
+
+func NewServer() *Server {
+	return &Server{}
+}
+
+// AddMachine adds a machine to the cluster.
+func (s *Server) AddMachine(ctx context.Context, req *pb2.AddMachineRequest) (*pb2.AddMachineResponse, error) {
+	return &pb2.AddMachineResponse{}, nil
+}