feat: Add new contact and message tracking features, including unread status and removal functionality

lib/services/meshcore_ble_service.dart

@@ -395,6 +395,15 @@ class MeshCoreBleService {
     await _commandSender.writeData(FrameBuilder.buildResetPath(contactPublicKey));
   }
 
+  /// Remove a contact from the companion radio
+  Future<void> removeContact(Uint8List contactPublicKey) async {
+    print('🗑️ [BLE] Removing contact from companion radio:');
+    print('    Public key prefix: ${contactPublicKey.sublist(0, 6).map((b) => b.toRadixString(16).padLeft(2, '0')).join(':')}');
+
+    await _commandSender.writeData(FrameBuilder.buildRemoveContact(contactPublicKey));
+    print('✅ [BLE] CMD_REMOVE_CONTACT sent');
+  }
+
   /// Clear packet logs
   void clearPacketLogs() {
     _commandSender.clearPacketLogs();

lib/services/message_storage_service.dart

@@ -128,6 +128,7 @@ class MessageStorageService {
       'recipientPublicKey': message.recipientPublicKey != null
           ? base64Encode(message.recipientPublicKey!)
           : null,
+      'isRead': message.isRead,
     };
   }
 
@@ -180,6 +181,7 @@ class MessageStorageService {
             ? Uint8List.fromList(
                 base64Decode(json['recipientPublicKey'] as String))
             : null,
+        isRead: json['isRead'] as bool? ?? false,
       );
     } catch (e) {
       print('❌ [MessageStorage] Error parsing message from JSON: $e');

lib/services/protocol/frame_builder.dart

@@ -235,4 +235,12 @@ class FrameBuilder {
     writer.writeBytes(contactPublicKey); // 32 bytes
     return writer.toBytes();
   }
+
+  /// Build RemoveContact command - removes a contact from the device
+  static Uint8List buildRemoveContact(Uint8List contactPublicKey) {
+    final writer = BufferWriter();
+    writer.writeByte(MeshCoreConstants.cmdRemoveContact); // 0x0F (15)
+    writer.writeBytes(contactPublicKey); // 32 bytes
+    return writer.toBytes();
+  }
 }