Add ESP32 MAC address retrieval in ESPTouch v2

Author: curious-panda7

lib/src/protocol.dart

@@ -127,7 +127,10 @@ abstract class Protocol {
   /// Receive data and returns response with device BSSID
   ///
   /// Throws [InvalidProvisioningResponseDataException] if data of received response is invalid
-  ProvisioningResponse receive(Uint8List data) {
+  ///
+  /// Added optional [sourceAddress] so derived protocols can extract IP address
+  /// from the UDP packet source when available.
+  ProvisioningResponse receive(Uint8List data, [InternetAddress? sourceAddress]) {
     if (data.length < 7) {
       throw InvalidProvisioningResponseDataException(
           "Invalid data ($data). Length should be at least 7 elements");

lib/src/protocols/esptouch.dart

@@ -1,3 +1,4 @@
+import 'dart:io';
 import 'dart:typed_data';
 
 import 'package:esp_smartconfig/esp_smartconfig.dart';
@@ -85,8 +86,11 @@ class EspTouch extends Protocol {
   /// Receive data and returns response with device BSSID and IP address
   ///
   /// Throws [InvalidProvisioningResponseDataException] if received data is not valid
+  ///
+  /// Signature updated to match [Protocol.receive] and support optional
+  /// source address forwarding from [Provisioner].
   @override
-  ProvisioningResponse receive(Uint8List data) {
+  ProvisioningResponse receive(Uint8List data, [InternetAddress? sourceAddress]) {
     final response = super.receive(data);
 
     if (data[0] != _expectedResponseFirstByte) {

lib/src/protocols/esptouch_v2.dart

@@ -18,7 +18,8 @@ class EspTouchV2 extends Protocol {
   List<int> get ports => [18266, 28266, 38266, 48266];
 
   @override
-  ProvisioningResponse receive(Uint8List data, InternetAddress? sourceAddress) {
+  ProvisioningResponse receive(Uint8List data, [InternetAddress? sourceAddress]) {
+  // Allow optional source address to be passed through from Provisioner.
     if (data.length < 7) {
       throw InvalidProvisioningResponseDataException(
         "Invalid data ($data). Length should be at least 7 elements",

lib/src/provisioner.dart

@@ -155,7 +155,9 @@ class Provisioner {
             }
 
             try {
-              final response = protocol.receive(pkg.data);
+              // Pass the UDP packet source address to protocol.receive so V2
+              // protocols can extract the device IP from the response.
+              final response = protocol.receive(pkg.data, pkg.address);
 
               if (protocol.findResponse(response) != null) {
                 // Same response already received