refactor(ui): 替换CDN资源为本地文件并统一按钮样式

- 将Font Awesome从CDN引用改为本地文件/css/all.min.css
- 为所有按钮添加图标以提升用户体验
- 修复登出弹窗的DOM加载问题
- 更新config.php中的数据库和SMTP配置

admin/editapp.php

@@ -128,7 +128,7 @@ if ($_SERVER['REQUEST_METHOD'] === 'POST' && isset($_POST['edit_app'])) {
     <!-- Bootstrap CSS -->
     <link href="../css/bootstrap.min.css" rel="stylesheet">
     <!-- Font Awesome -->
-    <link rel="stylesheet" href="https://cdnjs.cloudflare.com/ajax/libs/font-awesome/6.0.0/css/all.min.css">
+    <link rel="stylesheet" href="/css/all.min.css">
     <!-- 自定义CSS -->
     <link rel="stylesheet" href="../styles.css">
     <script src="/js/sweetalert.js"></script>
@@ -301,7 +301,7 @@ if ($_SERVER['REQUEST_METHOD'] === 'POST' && isset($_POST['edit_app'])) {
                 <input class="form-control" type="file" id="images" name="images[]" multiple>
             </div>
             <button type="submit" name="edit_app" class="btn btn-primary"><i class="fas fa-save me-2"></i>保存修改</button>
-            <a href="index.php" class="btn btn-secondary ms-2">取消</a>
+            <a href="index.php" class="btn btn-secondary ms-2"><i class="fas fa-times me-1"></i>取消</a>
         </form>
     </div>