refactor: move cmd handlers to cmd/cli/commands/ following tag_file architecture

cmd/cli/commands/billing/billing.go

@@ -0,0 +1,37 @@
+package billing
+
+import (
+	"fmt"
+
+	"git.yoresee.cc/nightstar/ry/internal/output"
+	"git.yoresee.cc/nightstar/ry/internal/provider"
+
+	"github.com/spf13/cobra"
+)
+
+func Cmd(prov *provider.Provider, 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 {
+			svc := (*prov).Billing()
+			if svc == nil {
+				return fmt.Errorf("billing not supported by current provider")
+			}
+			orders, err := svc.Orders(cmd.Context())
+			if err != nil {
+				return err
+			}
+			return (*out).Print(orders)
+		},
+	}
+
+	billingCmd.AddCommand(ordersCmd)
+
+	return billingCmd
+}