Create wifi backend abstraction

internal/config/config.go

@@ -11,6 +11,7 @@ import (
 type Config struct {
 	Bind                 string
 	WifiInterface        string
+	WifiBackend          string
 	UseARPDiscovery      bool
 	DHCPLeasesPath       string
 	ARPTablePath         string
@@ -75,6 +76,11 @@ func ConsolidateConfig() (opts *Config, err error) {
 		return
 	}
 
+	// Validate configuration
+	if opts.WifiBackend != "iwd" && opts.WifiBackend != "wpasupplicant" {
+		log.Fatalf("wifi-backend must be set to 'iwd' or 'wpasupplicant' (got: '%s')", opts.WifiBackend)
+	}
+
 	return
 }