feat: add actor user column to events and dashboard tables

Co-authored-by: Cursor <cursoragent@cursor.com>

frontend/src/views/DashboardView.vue

@@ -236,6 +236,8 @@
 
           <th>Имя сервера</th>
 
+          <th>Пользователь</th>
+
           <th>Версия агента</th>
 
           <th>Severity</th>
@@ -270,6 +272,8 @@
 
           <td>{{ formatServerName(e.display_name) }}</td>
 
+          <td>{{ e.actor_user || "—" }}</td>
+
           <td>{{ e.product_version || "—" }}</td>
 
           <td :class="'sev-' + e.severity">{{ e.severity }}</td>