fix: stop aggressive 2s chat polling, use WebSocket instead

- Add refetchChatMessages + refetchChatConversations to
  refetchAllCrmQueries so WebSocket dashboard.changed events
  cover pilot chat updates
- Reduce background polling from 2s to 30s (fallback only)

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

frontend/app/components/workspace/CrmWorkspaceApp.vue

@@ -308,6 +308,8 @@ async function refetchAllCrmQueries() {
     refetchFeed(),
     refetchPins(),
     refetchDocuments(),
+    refetchChatMessages(),
+    refetchChatConversations(),
   ]);
   await refreshSelectedClientTimeline();
 }