rebrand: frp -> kanhole (kanhole server, kanholec client)

cmd/kanholec/sub/gui_stub.go

@@ -0,0 +1,23 @@
+//go:build !kanholec_gui
+
+package sub
+
+import (
+	"fmt"
+
+	"github.com/spf13/cobra"
+)
+
+func init() {
+	guiCmd := &cobra.Command{
+		Use:   "gui",
+		Short: "Start the kanholec graphical user interface",
+		RunE: func(cmd *cobra.Command, args []string) error {
+			fmt.Println("kanholec GUI is not available in this build.")
+			fmt.Println("To build with GUI support, install OpenGL and X11 dev libraries, then:")
+			fmt.Println("  CGO_ENABLED=1 go build -tags kanholec_gui -o kanholec ./cmd/kanholec")
+			return nil
+		},
+	}
+	rootCmd.AddCommand(guiCmd)
+}