fix(desktop): DeerFlow UI — ChatArea refactor + ai-elements + dead CSS cleanup

ChatArea retry button uses setInput instead of direct sendToGateway,
fix bootstrap spinner stuck for non-logged-in users,
remove dead CSS (aurora-title/sidebar-open/quick-action-chips),
add ai components (ReasoningBlock/StreamingText/ChatMode/ModelSelector/TaskProgress),
add ClassroomPlayer + ResizableChatLayout + artifact panel

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

desktop/src/App.tsx

@@ -29,6 +29,7 @@ import { useProposalNotifications, ProposalNotificationHandler } from './lib/use
 import { useToast } from './components/ui/Toast';
 import type { Clone } from './store/agentStore';
 import { createLogger } from './lib/logger';
+import { startOfflineMonitor } from './store/offlineStore';
 
 const log = createLogger('App');
 
@@ -86,6 +87,8 @@ function App() {
 
   useEffect(() => {
     document.title = 'ZCLAW';
+    const stopOfflineMonitor = startOfflineMonitor();
+    return () => { stopOfflineMonitor(); };
   }, []);
 
   // Restore SaaS session from OS keyring on startup (before auth gate)
@@ -152,8 +155,11 @@ function App() {
     let mounted = true;
 
     const bootstrap = async () => {
-      // 未登录时不启动 bootstrap
-      if (!useSaaSStore.getState().isLoggedIn) return;
+      // 未登录时不启动 bootstrap，直接结束 loading
+      if (!useSaaSStore.getState().isLoggedIn) {
+        setBootstrapping(false);
+        return;
+      }
 
       try {
         // Step 1: Check and start local gateway in Tauri environment