refactor: 优化RequirementModal UI设计和代码清理

主要更新:
- 🎨 UI改进:
  - 将头部背景改为苹果风格设计
  - 添加背景图片 /image/bg.png
  - 将图标替换为动态视频logo
  - 统一配色为蓝色系,移除紫色元素
  - 优化标题和副标题布局

- 🧹 代码清理:
  - 删除5个临时测试文件 (test-*.html)
  - 删除4个旧版本页面组件 (WorkflowPage V1-V3, ResultPage V1)
  - 保留当前使用的 WorkflowPageV4 和 ResultPageV2

- 🔧 细节调整:
  - 视频logo尺寸调整为 80x80px
  - 移除视频容器的圆角和阴影效果
  - 按钮颜色从紫色渐变改为蓝色渐变

项目结构更加清晰,界面设计更加现代化

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

@@ -148,20 +148,54 @@ const RequirementModal: React.FC<RequirementModalProps> = ({ isOpen, onClose, on
             onClick={(e) => e.stopPropagation()}
           >
             <div className="bg-white rounded-2xl shadow-2xl max-w-5xl w-full max-h-[90vh] overflow-hidden">
-              {/* 头部 */}
-              <div className="bg-gradient-to-r from-blue-600 to-purple-600 p-6 text-white">
-                <div className="flex items-center justify-between">
-                  <div>
-                    <h2 className="text-2xl font-bold mb-2">输入需求</h2>
-                    <p className="text-blue-100">请选择订单班类型并描述您的项目需求</p>
+              {/* 头部 - 苹果风格设计 */}
+              <div className="relative">
+                {/* 渐变背景 */}
+                <div 
+                  className="absolute inset-0 bg-gradient-to-br from-slate-50 via-white to-gray-50"
+                  style={{
+                    backgroundImage: 'url(/image/bg.png)',
+                    backgroundSize: '100% 100%',
+                    backgroundPosition: 'center',
+                    backgroundRepeat: 'no-repeat'
+                  }}
+                />
+                
+                {/* 内容区 */}
+                <div className="relative px-8 py-6">
+                  <div className="flex items-center justify-between">
+                    <div>
+                      <div className="flex items-center gap-4">
+                        <div className="w-20 h-20 overflow-hidden flex-shrink-0">
+                          <video
+                            src="https://ddcz-1315997005.cos.ap-nanjing.myqcloud.com/static/video/cloude.mp4"
+                            className="w-full h-full object-cover"
+                            autoPlay
+                            loop
+                            muted
+                            playsInline
+                            controls={false}
+                          />
+                        </div>
+                        <div>
+                          <h2 className="text-2xl font-bold bg-gradient-to-r from-gray-900 to-gray-600 bg-clip-text text-transparent">
+                            AI 智能需求分析
+                          </h2>
+                          <p className="text-gray-500 text-sm mt-1">选择业务场景，让AI为您定制专属解决方案</p>
+                        </div>
+                      </div>
+                    </div>
+                    <button
+                      onClick={onClose}
+                      className="w-10 h-10 bg-white hover:bg-gray-50 rounded-full shadow-sm hover:shadow-md transition-all duration-200 flex items-center justify-center group"
+                    >
+                      <X className="w-5 h-5 text-gray-400 group-hover:text-gray-600 transition-colors" />
+                    </button>
                   </div>
-                  <button
-                    onClick={onClose}
-                    className="p-2 hover:bg-white/20 rounded-lg transition-colors"
-                  >
-                    <X className="w-6 h-6" />
-                  </button>
                 </div>
+                
+                {/* 底部分割线 */}
+                <div className="h-px bg-gradient-to-r from-transparent via-gray-200 to-transparent" />
               </div>
 
               <div className="p-6 max-h-[calc(90vh-120px)] overflow-y-auto">
@@ -258,7 +292,7 @@ const RequirementModal: React.FC<RequirementModalProps> = ({ isOpen, onClose, on
                       disabled={!requirement.trim() || !selectedOrderClass}
                       className={`px-6 py-2.5 rounded-lg font-medium transition-all flex items-center gap-2 ${
                         requirement.trim() && selectedOrderClass
-                          ? 'bg-gradient-to-r from-blue-600 to-purple-600 text-white hover:shadow-lg transform hover:scale-105'
+                          ? 'bg-gradient-to-r from-blue-500 to-blue-600 text-white hover:shadow-lg transform hover:scale-105'
                           : 'bg-gray-300 text-gray-500 cursor-not-allowed'
                       }`}
                     >