feat: Implement user blocking check in MessageRepository and ChatViewModel to ignore messages from blocked users

app/src/main/java/com/rosetta/messenger/ui/chats/ChatViewModel.kt

@@ -200,6 +200,12 @@ class ChatViewModel(application: Application) : AndroidViewModel(application) {
                 val privateKey = myPrivateKey ?: return@launch
                 val account = myPublicKey ?: return@launch
                 
+                // 🔥 Проверяем блокировку (как в Архиве)
+                val isBlocked = database.blacklistDao().isUserBlocked(packet.fromPublicKey, account)
+                if (isBlocked) {
+                    Log.d(TAG, "🚫 BLOCKED: Ignoring message from blocked user ${packet.fromPublicKey.take(20)}...")
+                    return@launch
+                }
                 
                 // Расшифровываем в фоне - получаем и текст и plainKeyAndNonce
                 val decryptResult = MessageCrypto.decryptIncomingFull(