refactor: centralize protobuf and remove go-zero

module/ec/order/pb/coupon.pb.gw.go

@@ -1,5 +1,5 @@
 // Code generated by protoc-gen-grpc-gateway. DO NOT EDIT.
-// source: coupon.proto
+// source: module/ec/order/proto/coupon.proto
 
 /*
 Package order is a reverse proxy.
@@ -43,6 +43,9 @@ func request_Coupon_ByStatus_0(ctx context.Context, marshaler runtime.Marshaler,
 	if err := marshaler.NewDecoder(req.Body).Decode(&protoReq); err != nil && !errors.Is(err, io.EOF) {
 		return nil, metadata, status.Errorf(codes.InvalidArgument, "%v", err)
 	}
+	if req.Body != nil {
+		_, _ = io.Copy(io.Discard, req.Body)
+	}
 	msg, err := client.ByStatus(ctx, &protoReq, grpc.Header(&metadata.HeaderMD), grpc.Trailer(&metadata.TrailerMD))
 	return msg, metadata, err
 }