修复部门搜索框UI样式重叠问题

将a-input-search改为a-input，避免自带搜索按钮与prefix图标重叠

frontend/src/views/Settings.vue

@@ -397,20 +397,18 @@
               />
 
               <!-- 部门搜索框 -->
-              <div style="margin-bottom: 16px;">
-                <a-input-search
+              <div style="margin-bottom: 16px; display: flex; align-items: center; gap: 12px;">
+                <a-input
                   v-model:value="departmentSearchText"
                   placeholder="搜索部门名称、编码或负责人"
                   allow-clear
-                  @search="onDepartmentSearch"
-                  @change="onDepartmentSearch"
                   style="max-width: 400px;"
                 >
                   <template #prefix>
                     <Icon name="search" size="sm" />
                   </template>
-                </a-input-search>
-                <span v-if="departmentSearchText" style="margin-left: 12px; color: #888; font-size: 13px;">
+                </a-input>
+                <span v-if="departmentSearchText" style="color: #888; font-size: 13px;">
                   找到 {{ filteredDepartments.length }} 个部门
                 </span>
               </div>