优化页面布局

- 当无对话时隐藏对话列表
- 调整主页表单位置

src/pages/index.vue

@@ -133,7 +133,7 @@ onMounted(() => {
   <el-container style="margin: 0; height: 100%; flex-direction: column;">
     <!-- 内层容器：自动填充剩余高度 -->
     <el-main class="main" style="flex: 1; min-height: 0;">
-      <div class="flex flex-col items-center justify-center">
+      <div class="flex flex-col items-center justify-center pt-30">
         <el-form
           ref="ruleFormRef"
           style="max-width: 600px"

src/pages/nav/HazardCheckResult/index.vue

@@ -404,7 +404,7 @@ onMounted(() => {
             </el-row>
           </el-col>
         </el-row>
-        <el-row style="flex: 1; overflow-y: auto; border-top: 1px solid var(--ep-border-color);">
+        <el-row v-if="data.对话列表.length > 0" style="flex: 1; overflow-y: auto; border-top: 1px solid var(--ep-border-color);">
           <SubtitleList title="对话" :data="data.对话列表" @click="(item: any[]) => handleJumpToTimePoint(Number(item[0]))" />
         </el-row>
         <!-- <el-row class="px-1 py-1">