fix: simplify button text in student list toolbar

app/templates/index.html

@@ -76,17 +76,17 @@
     <!-- 操作按钮行 -->
     <div class="d-flex flex-wrap gap-2 mb-3">
         <button class="btn btn-outline-secondary btn-sm" onclick="downloadTemplate()">
-            <i class="bi bi-download"></i> 模板下载
+            <i class="bi bi-download"></i> 模板
         </button>
         <button class="btn btn-outline-primary btn-sm" onclick="document.getElementById('importFileInput').click()">
-            <i class="bi bi-upload"></i> CSV导入
+            <i class="bi bi-upload"></i> 导入
         </button>
         <input type="file" id="importFileInput" accept=".csv" style="display:none" onchange="importStudents(this)">
         <button class="btn btn-outline-success btn-sm" onclick="exportStudents()">
             <i class="bi bi-file-arrow-up"></i> 导出
         </button>
         <button class="btn btn-primary btn-sm" onclick="showAddStudentModal()">
-            <i class="bi bi-plus-lg"></i> 新增学员
+            <i class="bi bi-plus-lg"></i> 新增
         </button>
     </div>