✨ 添加displayName字段显示解码后的文件名

- 后端返回文件列表时添加displayName字段（解码HTML实体）
- 前端使用displayName显示文件名，保持原始name用于操作

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude <noreply@anthropic.com>

backend/server.js

@@ -2279,6 +2279,7 @@ app.get('/api/files', authMiddleware, async (req, res) => {
 
       return {
         name: item.name,
+        displayName: decodeHtmlEntities(item.name),
         type: item.type === 'd' ? 'directory' : 'file',
         size: item.size,
         sizeFormatted: formatFileSize(item.size),

frontend/app.html

@@ -1373,7 +1373,7 @@
                 <i v-else-if="file.name.match(/\.(zip|rar|7z|tar|gz)$/i)" class="fas fa-file-archive" style="font-size: 64px; color: #795548;"></i>
                 <i v-else class="fas fa-file" style="font-size: 64px; color: #9E9E9E;"></i>
               </div>
-              <div class="file-name" :title="file.name">{{ file.name }}</div>
+            <div class="file-name" :title="file.displayName || file.name">{{ file.displayName || file.name }}</div>
             <div class="file-size">{{ file.isDirectory ? '文件夹' : file.sizeFormatted }}</div>
           </div>
         </div>
@@ -1419,7 +1419,7 @@
                     <i v-else-if="file.name.match(/\.(xls|xlsx)$/i)" class="fas fa-file-excel" style="font-size: 20px; color: #4CAF50; flex-shrink: 0;"></i>
                     <i v-else-if="file.name.match(/\.(zip|rar|7z|tar|gz)$/i)" class="fas fa-file-archive" style="font-size: 20px; color: #795548; flex-shrink: 0;"></i>
                     <i v-else class="fas fa-file" style="font-size: 20px; color: #9E9E9E; flex-shrink: 0;"></i>
-                    <span style="overflow: hidden; text-overflow: ellipsis; white-space: nowrap; flex: 1; min-width: 0;" :title="file.name">{{ file.name }}</span>
+                    <span style="overflow: hidden; text-overflow: ellipsis; white-space: nowrap; flex: 1; min-width: 0;" :title="file.displayName || file.name">{{ file.displayName || file.name }}</span>
                     </div>
                   </td>
                   <td style="padding: 10px; color: var(--text-secondary);">{{ file.isDirectory ? '-' : file.sizeFormatted }}</td>