feat(cmd/ry): migrate rainyun-cli to SDK-backed cmd/ry

- 删除 CLI 自带 provider/HTTP 层,全部改调 sdk.New(apiKey)
- config 简化为单一 apikey + output
- 补 SDK 4 个缺口端点(domain list / dns list / bucket-by-instance / expense orders)
- 修 output --raw bug(新增 raw case)
- 命令 ID 参数统一 int,显示 model ID 保持 string
- reinstall flag 从 --os 改 --os-id int

cmd/ry/commands/billing/billing.go

@@ -0,0 +1,50 @@
+package billing
+
+import (
+	"strconv"
+	"time"
+
+	"github.com/XingfenD/rainyun_api_go_sdk/apis/common"
+	"github.com/XingfenD/rainyun_api_go_sdk/apis/expense"
+	"github.com/XingfenD/rainyun_api_go_sdk/cmd/ry/internal/model"
+	"github.com/XingfenD/rainyun_api_go_sdk/cmd/ry/internal/output"
+	"github.com/XingfenD/rainyun_api_go_sdk/sdk"
+
+	"github.com/spf13/cobra"
+)
+
+func Cmd(rySDK **sdk.RainyunSDK, out **output.Printer) *cobra.Command {
+	billingCmd := &cobra.Command{
+		Use:   "billing",
+		Short: "Billing and orders",
+	}
+
+	ordersCmd := &cobra.Command{
+		Use:   "orders",
+		Short: "List orders",
+		RunE: func(cmd *cobra.Command, args []string) error {
+			resp, err := (*rySDK).GetOrdersList(&expense.GetOrdersListRequest{
+				Options: common.StandQueryParameters{Page: 1, PerPage: 50},
+			})
+			if err != nil {
+				return err
+			}
+			orders := make([]model.Order, len(resp.Data.Records))
+			for i, r := range resp.Data.Records {
+				t, _ := time.Parse("2006-01-02 15:04:05", r.CreateDate)
+				orders[i] = model.Order{
+					ID:      strconv.Itoa(r.ID),
+					Product: r.ProductName,
+					Amount:  r.Amount,
+					Status:  r.Status,
+					Created: t,
+				}
+			}
+			return (*out).Print(orders)
+		},
+	}
+
+	billingCmd.AddCommand(ordersCmd)
+
+	return billingCmd
+}