fix

Author: gsanchietti

service/messages.go

@@ -242,11 +242,7 @@ func (s *MessageService) FetchMessages(ctx context.Context, req *models.FetchMes
 	}
 
 	// Resolve username to Matrix ID using mappings
-	// The Validate function already matched the userName, so use the first mapping
-	userID := id.UserID("")
-	if len(mappings) > 0 {
-		userID = id.UserID(strings.TrimSpace(mappings[0].MatrixID))
-	}
+	userID := s.resolveMatrixUser(userName)
 	if userID == "" {
 		logger.Warn().Str("username", userName).Msg("resolved to empty Matrix user ID")
 		return nil, ErrAuthentication