cli: add headscale auth register/approve commands

Add a new 'headscale auth' command group with two subcommands:

  headscale auth register --auth-id <id> --user <user>
  headscale auth approve --auth-id <id>

These replace the old 'headscale nodes register --key' workflow.
The old command is marked deprecated with a pointer to the new one.

Updates #1850

cmd/headscale/cli/auth.go

@@ -0,0 +1,70 @@
+package cli
+
+import (
+	"context"
+	"fmt"
+
+	v1 "github.com/juanfont/headscale/gen/go/headscale/v1"
+	"github.com/spf13/cobra"
+)
+
+func init() {
+	rootCmd.AddCommand(authCmd)
+
+	authRegisterCmd.Flags().StringP("user", "u", "", "User")
+	authRegisterCmd.Flags().String("auth-id", "", "Auth ID")
+	mustMarkRequired(authRegisterCmd, "user", "auth-id")
+	authCmd.AddCommand(authRegisterCmd)
+
+	authApproveCmd.Flags().String("auth-id", "", "Auth ID")
+	mustMarkRequired(authApproveCmd, "auth-id")
+	authCmd.AddCommand(authApproveCmd)
+}
+
+var authCmd = &cobra.Command{
+	Use:   "auth",
+	Short: "Manage node authentication and approval",
+}
+
+var authRegisterCmd = &cobra.Command{
+	Use:   "register",
+	Short: "Register a node to your network",
+	RunE: grpcRunE(func(ctx context.Context, client v1.HeadscaleServiceClient, cmd *cobra.Command, args []string) error {
+		user, _ := cmd.Flags().GetString("user")
+		authID, _ := cmd.Flags().GetString("auth-id")
+
+		request := &v1.AuthRegisterRequest{
+			AuthId: authID,
+			User:   user,
+		}
+
+		response, err := client.AuthRegister(ctx, request)
+		if err != nil {
+			return fmt.Errorf("registering node: %w", err)
+		}
+
+		return printOutput(
+			cmd,
+			response.GetNode(),
+			fmt.Sprintf("Node %s registered", response.GetNode().GetGivenName()))
+	}),
+}
+
+var authApproveCmd = &cobra.Command{
+	Use:   "approve",
+	Short: "Approve a pending authentication request",
+	RunE: grpcRunE(func(ctx context.Context, client v1.HeadscaleServiceClient, cmd *cobra.Command, args []string) error {
+		authID, _ := cmd.Flags().GetString("auth-id")
+
+		request := &v1.AuthApproveRequest{
+			AuthId: authID,
+		}
+
+		response, err := client.AuthApprove(ctx, request)
+		if err != nil {
+			return fmt.Errorf("approving auth request: %w", err)
+		}
+
+		return printOutput(cmd, response, "Auth request approved")
+	}),
+}

cmd/headscale/cli/debug.go

@@ -37,7 +37,7 @@ var createNodeCmd = &cobra.Command{
 		name, _ := cmd.Flags().GetString("name")
 		registrationID, _ := cmd.Flags().GetString("key")
 
-		_, err := types.RegistrationIDFromString(registrationID)
+		_, err := types.AuthIDFromString(registrationID)
 		if err != nil {
 			return fmt.Errorf("parsing machine key: %w", err)
 		}

cmd/headscale/cli/nodes.go

@@ -63,8 +63,9 @@ var nodeCmd = &cobra.Command{
 }
 
 var registerNodeCmd = &cobra.Command{
-	Use:   "register",
-	Short: "Registers a node to your network",
+	Use:        "register",
+	Short:      "Registers a node to your network",
+	Deprecated: "use 'headscale auth register --auth-id <id> --user <user>' instead",
 	RunE: grpcRunE(func(ctx context.Context, client v1.HeadscaleServiceClient, cmd *cobra.Command, args []string) error {
 		user, _ := cmd.Flags().GetString("user")
 		registrationID, _ := cmd.Flags().GetString("key")