Add LPCNet voice mode option

test/providers/contacts_provider_test.dart

@@ -1,5 +1,6 @@
 import 'dart:typed_data';
 
+import 'package:geolocator/geolocator.dart';
 import 'package:flutter_test/flutter_test.dart';
 import 'package:latlong2/latlong.dart';
 import 'package:meshcore_sar_app/models/contact.dart';
@@ -522,6 +523,58 @@ void main() {
         isEmpty,
       );
     });
+
+    test('infers a fallback location 100m from first-hop repeater', () {
+      final repeaterKey = Uint8List.fromList([
+        0xAA,
+        0xBB,
+        0x10,
+        0x11,
+        0x12,
+        0x13,
+        ...List<int>.generate(26, (index) => index + 20),
+      ]);
+      provider.addOrUpdateContact(
+        createContact(
+          key: repeaterKey,
+          type: ContactType.repeater,
+          name: 'Relay Alpha',
+        ),
+      );
+
+      final targetKey = createPublicKey(120);
+      final route = ContactRouteCodec.parse('AABB,CCDD');
+      provider.addOrUpdateContact(
+        Contact(
+          publicKey: targetKey,
+          type: ContactType.chat,
+          flags: 0,
+          outPathLen: route.signedEncodedPathLen,
+          outPath: route.paddedPathBytes,
+          advName: 'No GPS',
+          lastAdvert: DateTime.now().millisecondsSinceEpoch ~/ 1000,
+          advLat: 0,
+          advLon: 0,
+          lastMod: DateTime.now().millisecondsSinceEpoch ~/ 1000,
+        ),
+      );
+
+      final updated = provider.findContactByKey(targetKey)!;
+      final inferred = updated.displayLocation;
+      final repeater = provider.findContactByKey(repeaterKey)!;
+      final repeaterLocation = repeater.displayLocation;
+
+      expect(inferred, isNotNull);
+      expect(repeaterLocation, isNotNull);
+
+      final distanceMeters = Geolocator.distanceBetween(
+        repeaterLocation!.latitude,
+        repeaterLocation.longitude,
+        inferred!.latitude,
+        inferred.longitude,
+      );
+      expect(distanceMeters, closeTo(100.0, 8.0));
+    });
   });
 
   group('ContactsProvider.updateFastGps', () {

test/services/message_storage_service_test.dart

@@ -0,0 +1,101 @@
+import 'dart:typed_data';
+
+import 'package:flutter_test/flutter_test.dart';
+import 'package:meshcore_client/meshcore_client.dart';
+import 'package:meshcore_sar_app/models/message_reception_details.dart';
+import 'package:meshcore_sar_app/services/message_storage_service.dart';
+import 'package:shared_preferences/shared_preferences.dart';
+
+void main() {
+  TestWidgetsFlutterBinding.ensureInitialized();
+
+  setUp(() {
+    SharedPreferences.setMockInitialValues({});
+  });
+
+  test(
+    'retains path bytes for stored unread message when reception sidecar is missing',
+    () async {
+      final storage = MessageStorageService();
+      final message = Message(
+        id: 'msg-1',
+        messageType: MessageType.contact,
+        senderPublicKeyPrefix: Uint8List.fromList([1, 2, 3, 4, 5, 6]),
+        pathLen: 2,
+        textType: MessageTextType.plain,
+        senderTimestamp: 1700000000,
+        text: 'Unread message',
+        receivedAt: DateTime.fromMillisecondsSinceEpoch(1700000000500),
+        isRead: false,
+      );
+
+      await storage.saveMessages(
+        [message],
+        messageReceptionDetails: {
+          message.id: MessageReceptionDetails(
+            capturedAt: DateTime.fromMillisecondsSinceEpoch(1700000000600),
+            pathBytes: const [0xAA, 0xBB, 0xCC],
+          ),
+        },
+      );
+
+      final prefs = await SharedPreferences.getInstance();
+      await prefs.remove('stored_message_reception_details');
+
+      final restoredDetails = await storage.loadMessageReceptionDetails();
+
+      expect(restoredDetails.keys, contains(message.id));
+      expect(restoredDetails[message.id]?.pathBytes, [0xAA, 0xBB, 0xCC]);
+    },
+  );
+
+  test('retains embedded reception details when sidecar is missing', () async {
+    final storage = MessageStorageService();
+    final message = Message(
+      id: 'msg-2',
+      messageType: MessageType.channel,
+      senderPublicKeyPrefix: Uint8List.fromList([6, 5, 4, 3, 2, 1]),
+      channelIdx: 2,
+      pathLen: 3,
+      textType: MessageTextType.plain,
+      senderTimestamp: 1700000100,
+      text: 'Room update',
+      receivedAt: DateTime.fromMillisecondsSinceEpoch(1700000100500),
+      isRead: false,
+    );
+
+    await storage.saveMessages(
+      [message],
+      messageReceptionDetails: {
+        message.id: MessageReceptionDetails(
+          capturedAt: DateTime.fromMillisecondsSinceEpoch(1700000100600),
+          packetLoggedAt: DateTime.fromMillisecondsSinceEpoch(1700000100400),
+          rssiDbm: -91,
+          snrDb: 7.25,
+          pathBytes: const [0xAA, 0xBB, 0xCC, 0xDD],
+          senderToReceiptMs: 1200,
+          estimatedTransmitMs: 800,
+          postTransmitDelayMs: 400,
+        ),
+      },
+    );
+
+    final prefs = await SharedPreferences.getInstance();
+    await prefs.remove('stored_message_reception_details');
+
+    final restoredDetails = await storage.loadMessageReceptionDetails();
+    final restored = restoredDetails[message.id];
+
+    expect(restored, isNotNull);
+    expect(restored!.pathBytes, [0xAA, 0xBB, 0xCC, 0xDD]);
+    expect(restored.rssiDbm, -91);
+    expect(restored.snrDb, 7.25);
+    expect(restored.senderToReceiptMs, 1200);
+    expect(restored.estimatedTransmitMs, 800);
+    expect(restored.postTransmitDelayMs, 400);
+    expect(
+      restored.packetLoggedAt,
+      DateTime.fromMillisecondsSinceEpoch(1700000100400),
+    );
+  });
+}