fix(web): reconcile unread mention counters in realtime

web/src/hooks/useRealtime.ts

@@ -102,7 +102,7 @@ export function useRealtime() {
               ws.send(JSON.stringify({ event: "message_read", payload: { chat_id: chatId, message_id: message.id } }));
               chatStore.clearUnread(chatId);
             } else if (wasInserted) {
-              chatStore.incrementUnread(chatId);
+              chatStore.incrementUnread(chatId, hasMentionForUser(message.text, authStore.me?.username ?? null));
             }
             maybeShowBrowserNotification(chatId, message, chatStore.activeChatId);
           }
@@ -331,3 +331,21 @@ function maybeShowBrowserNotification(chatId: number, message: Message, activeCh
     };
   })();
 }
+
+function hasMentionForUser(text: string | null, username: string | null): boolean {
+  if (!text || !username) {
+    return false;
+  }
+  const normalizedUsername = username.toLowerCase();
+  const mentionRegex = /(^|[^A-Za-z0-9_])@([A-Za-z0-9_]{3,50})(?![A-Za-z0-9_])/g;
+  let match: RegExpExecArray | null;
+  while (true) {
+    match = mentionRegex.exec(text);
+    if (!match) {
+      return false;
+    }
+    if ((match[2] ?? "").toLowerCase() === normalizedUsername) {
+      return true;
+    }
+  }
+}