Fix read receipts: mark visible messages as read immediately

client-web/src/modules/chats/presentation/components/ChatView.tsx

@@ -573,6 +573,7 @@ export default function ChatView({ onStartCall, onStartGroupCall }: { onStartCal
       {
         root: scrollContainerRef.current,
         threshold: 0.1,
+        rootMargin: '0px',
       }
     );
 
@@ -584,7 +585,26 @@ export default function ChatView({ onStartCall, onStartGroupCall }: { onStartCal
       unreadElements.forEach((el: Element) => {
         const id = el.getAttribute('data-message-id');
         if (id && !sentReadIdsRef.current.has(id)) {
-          observer.observe(el);
+          // Check if element is already visible
+          const rect = el.getBoundingClientRect();
+          const containerRect = scrollContainerRef.current!.getBoundingClientRect();
+          const isVisible = rect.top >= containerRect.top && rect.bottom <= containerRect.bottom;
+
+          if (isVisible) {
+            // Mark as read immediately without waiting for intersection
+            const seqId = parseInt(el.getAttribute('data-sequence-id') || '0', 10);
+            if (seqId > 0) {
+              socket.emit('read_messages', {
+                chatId: activeChat,
+                lastReadMessageId: id,
+                lastReadSequenceId: seqId,
+              });
+              useChatStore.getState().markRead(activeChat, user.id, seqId);
+              sentReadIdsRef.current.add(id);
+            }
+          } else {
+            observer.observe(el);
+          }
         }
       });
     };