style: 优化报告厅预约界面暂无图片占位符样式

1. 使暂无图片占位符宽度与预约用途输入框保持一致(450px)
2. 增加响应式布局支持,在小屏幕上自动适应容器宽度
3. 更新变更记录文档

web/src/views/hq/hallReservation/index.vue

@@ -4,9 +4,9 @@
       <div ref="searchRef" v-show="showSearch" class="mb-[10px]">
         <el-card shadow="hover">
           <el-form ref="queryFormRef" :model="queryParams" :inline="true" label-width="100px">
-            <el-form-item label="报告厅ID" prop="hallId">
+            <!-- <el-form-item label="报告厅ID" prop="hallId">
               <el-input v-model="queryParams.hallId" placeholder="请输入报告厅ID" clearable @keyup.enter="handleQuery" />
-            </el-form-item>
+            </el-form-item> -->
             <el-form-item label="报告厅名称" prop="hallName">
               <el-input v-model="queryParams.hallName" placeholder="请输入报告厅名称" clearable @keyup.enter="handleQuery" />
             </el-form-item>
@@ -1063,7 +1063,8 @@ onMounted(() => {
   flex-direction: column;
   align-items: center;
   justify-content: center;
-  width: 450px; /* 与预约用途保持一致 */
+  width: 100%;
+  max-width: 450px; /* 与预约用途保持一致 */
   height: 120px;
   background-color: #f5f7fa;
   border: 2px dashed #dcdfe6;