feat: нормальная работа с группами

lib/models/chat_info.dart

@@ -23,6 +23,16 @@ class ChatInfo {
   bool isAdmin(int id) => adminIds.contains(id);
   bool isOwner(int id) => owner != null && id == owner;
 
+  String? adminAlias(int id) {
+    final source = raw['adminParticipants'];
+    if (source is! Map) return null;
+    final entry = source[id.toString()] ?? source[id];
+    if (entry is! Map) return null;
+    final alias = entry['alias'];
+    if (alias is String && alias.trim().isNotEmpty) return alias.trim();
+    return null;
+  }
+
   int? get participantsCount => raw['participantsCount'] as int?;
   int? get blockedParticipantsCount => raw['blockedParticipantsCount'] as int?;
   String? get link => raw['link'] as String?;

lib/models/contact_info.dart

@@ -69,5 +69,10 @@ class ContactInfo {
 
   bool get isBot => options.contains('BOT');
 
+  bool get isDeleted {
+    final status = raw['accountStatus'];
+    return status is int && status != 0;
+  }
+
   int? get id => raw['id'] as int?;
 }