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/components/FirstConversationPrompt.tsx

@@ -22,13 +22,16 @@ import {
 } from '../lib/personality-presets';
 import type { Clone } from '../store/agentStore';
 import { useChatStore } from '../store/chatStore';
+import { useClassroomStore } from '../store/classroomStore';
+import { useHandStore } from '../store/handStore';
 
 // Quick action chip definitions — DeerFlow-style colored pills
+// handId maps to actual Hand names in the runtime
 const QUICK_ACTIONS = [
   { key: 'surprise', label: '小惊喜', icon: Sparkles, color: 'text-orange-500' },
   { key: 'write', label: '写作', icon: PenLine, color: 'text-blue-500' },
-  { key: 'research', label: '研究', icon: Microscope, color: 'text-purple-500' },
-  { key: 'collect', label: '收集', icon: Layers, color: 'text-green-500' },
+  { key: 'research', label: '研究', icon: Microscope, color: 'text-purple-500', handId: 'researcher' },
+  { key: 'collect', label: '收集', icon: Layers, color: 'text-green-500', handId: 'collector' },
   { key: 'learn', label: '学习', icon: GraduationCap, color: 'text-indigo-500' },
 ];
 
@@ -69,6 +72,41 @@ export function FirstConversationPrompt({
   });
 
   const handleQuickAction = (key: string) => {
+    if (key === 'learn') {
+      // Trigger classroom generation flow
+      const classroomStore = useClassroomStore.getState();
+      // Extract a clean topic from the prompt
+      const prompt = QUICK_ACTION_PROMPTS[key] || '';
+      const topic = prompt
+        .replace(/^[你我].*?(想了解|想学|了解|学习|分析|研究|探索)\s*/g, '')
+        .replace(/[，。？！].*$/g, '')
+        .replace(/^(能|帮|请|可不可以).*/g, '')
+        .trim() || '互动课堂';
+      classroomStore.startGeneration({
+        topic,
+        style: 'lecture',
+        level: 'intermediate',
+        language: 'zh-CN',
+      }).catch(() => {
+        // Error is already stored in classroomStore.error and displayed in ChatArea
+      });
+      return;
+    }
+
+    // Check if this action maps to a Hand
+    const actionDef = QUICK_ACTIONS.find((a) => a.key === key);
+    if (actionDef?.handId) {
+      const handStore = useHandStore.getState();
+      handStore.triggerHand(actionDef.handId, {
+        action: key === 'research' ? 'report' : 'collect',
+        query: { query: QUICK_ACTION_PROMPTS[key] || '' },
+      }).catch(() => {
+        // Fallback: fill prompt into input bar
+        onSelectSuggestion?.(QUICK_ACTION_PROMPTS[key] || '你好！');
+      });
+      return;
+    }
+
     const prompt = QUICK_ACTION_PROMPTS[key] || '你好！';
     onSelectSuggestion?.(prompt);
   };