style(agent): 优化工作流页面样式

- 移除工作流卡片标题的自定义颜色样式- 优化 Markdown 渲染容器的样式，确保图片自适应- 调整历史记录项弹出框的样式，使其背景透明无圆角

src/views/agent/work-flow/index.vue

@@ -42,7 +42,7 @@
                 {{ item.title }}
               </div>
               <a-trigger trigger="click" position="bottom" :auto-fit-position="true" :unmount-on-close="true">
-                <SvgIcon size="12" name="svg-more" class="color-#6D4CFE" style="float: right" />
+                <SvgIcon size="12" name="svg-more"  style="float: right" />
                 <template #content>
                   <div class="">
                     <div class="history-item-dropdown">
@@ -174,7 +174,7 @@ const workFlowRes = reactive({
 const renderedMarkdown = computed(() => {
   if (workFlowRes?.output) {
     const rawHtml = marked.parse(workFlowRes.output || '');
-    return DOMPurify.sanitize(rawHtml); // 防止 XSS 攻击
+    return DOMPurify.sanitize(rawHtml);
   }
   return '';
 });
@@ -300,4 +300,5 @@ onMounted(() => {
 
 <style scoped lang="scss">
 @import './style.scss';
+
 </style>