feat: add actor user column to events and dashboard tables

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

frontend/src/views/EventsView.vue

@@ -33,6 +33,7 @@
           <th>Время</th>
           <th>Хост</th>
           <th>Имя сервера</th>
+          <th>Пользователь</th>
           <th>Версия агента</th>
           <th>Severity</th>
           <th>Type</th>
@@ -47,6 +48,7 @@
           <td>{{ formatDt(e.occurred_at) }}</td>
           <td>{{ e.hostname }}</td>
           <td>{{ formatServerName(e.display_name) }}</td>
+          <td>{{ e.actor_user || "—" }}</td>
           <td>{{ e.product_version || "—" }}</td>
           <td :class="'sev-' + e.severity">{{ e.severity }}</td>
           <td><code>{{ e.type }}</code></td>