autoconnect on fly mode (does not work yet)

app/lib/transport/udp/udp_transport.dart

@@ -32,16 +32,22 @@ class UdpTransport implements LinkTransport {
     required Future<String?> Function() getHost,
     required Future<int> Function() getPort,
     required Future<String> Function() getSsidPrefix,
+    required Future<String?> Function() getRememberedSsid,
+    required Future<void> Function(String ssid) rememberSsid,
     MlrsNetworkController? networkController,
   })  : _getHost = getHost,
         _getPort = getPort,
         _getSsidPrefix = getSsidPrefix,
+        _getRememberedSsid = getRememberedSsid,
+        _rememberSsid = rememberSsid,
         _networkController =
             networkController ?? MethodChannelMlrsNetworkController();
 
   final Future<String?> Function() _getHost;
   final Future<int> Function() _getPort;
   final Future<String> Function() _getSsidPrefix;
+  final Future<String?> Function() _getRememberedSsid;
+  final Future<void> Function(String ssid) _rememberSsid;
   final MlrsNetworkController _networkController;
 
   final _incomingController = StreamController<Uint8List>.broadcast();
@@ -54,6 +60,7 @@ class UdpTransport implements LinkTransport {
   int? _boundPort;
   bool _socketOpen = false;
   bool? _staConcurrencySupported;
+  String? _connectedSsid;
 
   LinkState _state = LinkState.disconnected;
   LinkErrorReason? _lastErrorReason;
@@ -85,6 +92,13 @@ class UdpTransport implements LinkTransport {
   /// nicht ermittelbar (API < 30, Doku Abschnitt 4/8).
   bool? get staConcurrencySupported => _staConcurrencySupported;
 
+  /// Tatsaechliche SSID des verbundenen Netzes, sobald von Android
+  /// ermittelbar (Doku Abschnitt 8: "verbundenes WLAN anzeigen"). Wird bei
+  /// jedem erfolgreichen [connect] auch dauerhaft gemerkt (siehe
+  /// [_rememberSsid]), damit kuenftige Verbindungen exakt statt per Praefix
+  /// angefragt werden koennen.
+  String? get connectedSsid => _connectedSsid;
+
   @override
   Future<void> connect() async {
     _lastErrorReason = null;
@@ -92,13 +106,17 @@ class UdpTransport implements LinkTransport {
     _setState(LinkState.connecting);
 
     final ssidPrefix = await _getSsidPrefix();
+    final rememberedSsid = await _getRememberedSsid();
     final firstEvent = Completer<MlrsNetworkEvent>();
     final requestSub = _networkController.events.listen((event) {
       if (!firstEvent.isCompleted) firstEvent.complete(event);
     });
 
     try {
-      await _networkController.requestNetwork(ssidPrefix);
+      await _networkController.requestNetwork(
+        ssidPrefix,
+        preferredSsid: rememberedSsid,
+      );
       final event = await firstEvent.future;
       await requestSub.cancel();
 
@@ -115,6 +133,11 @@ class UdpTransport implements LinkTransport {
       // unten, nicht erst danach (Doku Abschnitt 8).
       _networkLossSub = _networkController.events.listen(_onNetworkEvent);
 
+      _connectedSsid = available.ssid;
+      if (available.ssid != null) {
+        await _rememberSsid(available.ssid!);
+      }
+
       final configuredHost = await _getHost();
       final configuredPort = await _getPort();
       final prefillHost = (configuredHost != null && configuredHost.isNotEmpty)
@@ -170,6 +193,7 @@ class UdpTransport implements LinkTransport {
     _packetSub?.cancel();
     _packetSub = null;
     _boundPort = null;
+    _connectedSsid = null;
     if (_socketOpen) {
       _socketOpen = false;
       unawaited(_networkController.closeSocket());
@@ -193,6 +217,7 @@ class UdpTransport implements LinkTransport {
     await _packetSub?.cancel();
     _packetSub = null;
     _boundPort = null;
+    _connectedSsid = null;
     if (_socketOpen) {
       _socketOpen = false;
       await _networkController.closeSocket();
@@ -220,9 +245,14 @@ class UdpTransport implements LinkTransport {
     _packetSub?.cancel();
     if (_socketOpen) {
       _socketOpen = false;
-      unawaited(_networkController.closeSocket());
+      // dispose() darf nie eine unbehandelte Future-Exception hinterlassen -
+      // z.B. wirft der Platform-Channel MissingPluginException, wenn
+      // ueberhaupt kein natives Gegenstueck existiert (Tests, Web/Desktop-
+      // UI-Vorschau). Der Aufrufer kann an dieser Stelle ohnehin nicht mehr
+      // reagieren.
+      unawaited(_networkController.closeSocket().catchError((_) {}));
     }
-    unawaited(_networkController.releaseNetwork());
+    unawaited(_networkController.releaseNetwork().catchError((_) {}));
     _networkController.dispose();
     _incomingController.close();
     _stateController.close();