Replace type assertions with runtime validation in AppHeader.tsx

Co-authored-by: hotlong <50353452+hotlong@users.noreply.github.com>

Author: Copilot

apps/console/src/components/AppHeader.tsx

@@ -66,8 +66,20 @@ export function AppHeader({ appName, objects, connectionState, presenceUsers, ac
           dataSource.find('sys_presence').catch(() => ({ data: [] })),
           dataSource.find('sys_activity', { $orderby: { timestamp: 'desc' }, $top: 20 }).catch(() => ({ data: [] })),
         ]);
-        if (presenceResult.data?.length) setApiPresenceUsers(presenceResult.data as PresenceUser[]);
-        if (activityResult.data?.length) setApiActivities(activityResult.data as ActivityItem[]);
+        if (presenceResult.data?.length) {
+          const data = presenceResult.data as Record<string, unknown>[];
+          const users = data.filter(
+            (u): u is PresenceUser & Record<string, unknown> => typeof u.userId === 'string'
+          );
+          if (users.length) setApiPresenceUsers(users);
+        }
+        if (activityResult.data?.length) {
+          const data = activityResult.data as Record<string, unknown>[];
+          const items = data.filter(
+            (a): a is ActivityItem & Record<string, unknown> => typeof a.type === 'string'
+          );
+          if (items.length) setApiActivities(items);
+        }
       } catch {
         // Fallback to defaults handled below
       }