Refactor code structure for improved readability and maintainability

platform/discoverer_darwin.go

@@ -0,0 +1,8 @@
+//go:build darwin
+
+package platform
+
+// NewNetworkDiscoverer returns the macOS-specific NetworkDiscoverer.
+func NewNetworkDiscoverer() NetworkDiscoverer {
+	return &DarwinNetworkDiscoverer{}
+}