feat: 优化展会演示界面和添加会展策划资源

详细修改:
- 移除ResultModal组件中的PDF下载按钮，简化用户界面
- 添加会展策划相关的Agent prompt文档(7个专家角色)
- 添加Agent头像图片资源(7个专家头像)
- 添加会展策划图片资源(包括展会场景、小米汽车、Whisk设计等)
- 添加汽车展会策划方案DEMO文档

影响模块:
- 前端展示界面优化
- 资源文件补充完善
- 会展策划演示系统增强

🤖 Generated with Claude Code

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

web_frontend/exhibition-demo/src/components/ResultModal.tsx

@@ -140,20 +140,14 @@ const ResultModal: React.FC<ResultModalProps> = ({ isOpen, onClose, onViewDetail
                 </div>
 
                 {/* 操作按钮 */}
-                <div className="flex gap-3">
+                <div className="flex justify-center">
                   <button
                     onClick={() => window.open('http://localhost:4155', '_blank')}
-                    className="flex-1 px-6 py-3 bg-gradient-to-r from-blue-600 to-purple-600 text-white rounded-xl font-medium hover:shadow-lg transform hover:scale-105 transition-all flex items-center justify-center gap-2"
+                    className="px-8 py-3 bg-gradient-to-r from-blue-600 to-purple-600 text-white rounded-xl font-medium hover:shadow-lg transform hover:scale-105 transition-all flex items-center justify-center gap-2"
                   >
                     <Eye className="w-5 h-5" />
                     查看详细方案
                   </button>
-                  <button
-                    className="flex-1 px-6 py-3 bg-gray-100 text-gray-700 rounded-xl font-medium hover:bg-gray-200 transition-colors flex items-center justify-center gap-2"
-                  >
-                    <Download className="w-5 h-5" />
-                    下载PDF
-                  </button>
                 </div>
               </div>
             </div>