Add tests. They are quite basic ...

config/config_test.go

@@ -0,0 +1,30 @@
+// Copyright 2025, IPng Networks GmbH, Pim van Pelt <pim@ipng.ch>
+
+package config
+
+import "testing"
+
+func TestDebugFlagDefault(t *testing.T) {
+	// Test that Debug flag starts as false by default
+	if Debug != false {
+		t.Errorf("Expected Debug to be false by default, got %v", Debug)
+	}
+}
+
+func TestDebugFlagSet(t *testing.T) {
+	// Save original value
+	original := Debug
+	defer func() { Debug = original }()
+
+	// Test setting Debug to true
+	Debug = true
+	if Debug != true {
+		t.Errorf("Expected Debug to be true after setting, got %v", Debug)
+	}
+
+	// Test setting Debug to false
+	Debug = false
+	if Debug != false {
+		t.Errorf("Expected Debug to be false after setting, got %v", Debug)
+	}
+}