修改

public/admin/tinymce/plugins/attachment/plugin.js

@@ -18,6 +18,12 @@
       console.warn('无法获取baseURL', e);
     }
     
+    // 注册自定义图标，使用 📎 emoji
+    var icons = editor.ui.registry.getAll().icons;
+    if (!icons || !icons.attachment) {
+      editor.ui.registry.addIcon('attachment', '<svg width="24" height="24" xmlns="http://www.w3.org/2000/svg"><foreignObject width="24" height="24"><div xmlns="http://www.w3.org/1999/xhtml" style="font-size: 18px; line-height: 24px; text-align: center;">📎</div></foreignObject></svg>');
+    }
+    
     editor.ui.registry.addButton('attachment', {
       icon: 'attachment',
       tooltip: '上传附件',