android: keep read ack strictly bounded by visible incoming messages

android/CHANGELOG.md

@@ -714,3 +714,8 @@
 - Improved cross-device sync (web <-> android):
   - `message_read` realtime event now parses `user_id` and `last_read_message_id`.
   - on `message_read`, Android refreshes chat snapshot from backend to keep unread counters aligned across devices.
+
+### Step 108 - Strict read boundary by visible incoming only
+- Removed fallback read-pointer advancement in `ChatViewModel.acknowledgeLatestMessages(...)` that previously moved `lastReadMessageId` by latest loaded message id.
+- Read pointer is now advanced only via `onVisibleIncomingMessageId(...)` from visible incoming rows in `ChatScreen`.
+- This prevents read acknowledgements from overshooting beyond what user actually saw during refresh/recompose scenarios.

android/app/src/main/java/ru/daemonlord/messenger/ui/chat/ChatViewModel.kt

@@ -656,7 +656,6 @@ class ChatViewModel @Inject constructor(
     }
 
     private fun acknowledgeLatestMessages(messages: List<MessageItem>) {
-        val latestVisible = messages.maxByOrNull { it.id } ?: return
         val latestIncoming = messages.asReversed().firstOrNull { !it.isOutgoing }
 
         if (latestIncoming != null && lastDeliveredMessageId != latestIncoming.id) {
@@ -665,9 +664,6 @@ class ChatViewModel @Inject constructor(
                 markMessageDeliveredUseCase(chatId = chatId, messageId = latestIncoming.id)
             }
         }
-        if ((lastReadMessageId ?: 0L) < latestVisible.id) {
-            lastReadMessageId = latestVisible.id
-        }
     }
 
     fun canEdit(message: MessageItem): Boolean {