feat(remote): 文件传输改用Electron IPC通道

- 主进程新增4个IPC handler处理远程文件操作
- 前端通过IPC调用而非浏览器fetch访问远程API
- Remote服务新增3003端口专门处理文件传输
- 上传使用文件路径方案，下载使用保存对话框方案

electron/main.ts

@@ -156,6 +156,142 @@ ipcMain.handle('clipboard-write-text', async (event, text: string) => {
   }
 });
 
+ipcMain.handle('remote-fetch-drives', async (_event, serverHost: string, port: number, password?: string) => {
+  try {
+    let url = `http://${serverHost}:${port}/api/files/drives`;
+    if (password) {
+      url += `?password=${encodeURIComponent(password)}`;
+    }
+    const response = await fetch(url);
+    if (!response.ok) {
+      throw new Error(`Failed to fetch drives: ${response.statusText}`);
+    }
+    const data = await response.json();
+    const items = data.items || [];
+    return {
+      success: true,
+      data: items.map((item: { name: string; isDirectory: boolean; size: number }) => ({
+        name: item.name,
+        path: item.name,
+        type: item.isDirectory ? 'dir' : 'file',
+        size: item.size,
+        modified: '',
+      }))
+    };
+  } catch (error: any) {
+    log.error('Remote fetch drives failed:', error);
+    return { success: false, error: error.message };
+  }
+});
+
+ipcMain.handle('remote-fetch-files', async (_event, serverHost: string, port: number, filePath: string, password?: string) => {
+  try {
+    let url = `http://${serverHost}:${port}/api/files/browse?path=${encodeURIComponent(filePath)}&allowSystem=true`;
+    if (password) {
+      url += `&password=${encodeURIComponent(password)}`;
+    }
+    const response = await fetch(url);
+    if (!response.ok) {
+      throw new Error(`Failed to fetch files: ${response.statusText}`);
+    }
+    const data = await response.json();
+    const items = data.items || [];
+    return {
+      success: true,
+      data: items.map((item: { name: string; isDirectory: boolean; size: number; modified: Date }) => ({
+        name: item.name,
+        path: data.currentPath ? `${data.currentPath}/${item.name}` : item.name,
+        type: item.isDirectory ? 'dir' : 'file',
+        size: item.size,
+        modified: item.modified?.toString(),
+      }))
+    };
+  } catch (error: any) {
+    log.error('Remote fetch files failed:', error);
+    return { success: false, error: error.message };
+  }
+});
+
+ipcMain.handle('remote-upload-file', async (_event, serverHost: string, port: number, filePath: string, remotePath: string, password?: string) => {
+  try {
+    const win = electronState.getMainWindow();
+    if (!win) {
+      throw new Error('No window found');
+    }
+
+    const fullPath = path.resolve(filePath);
+    if (!fs.existsSync(fullPath)) {
+      throw new Error('File not found');
+    }
+
+    const fileBuffer = fs.readFileSync(fullPath);
+    const fileName = path.basename(fullPath);
+
+    let url = `http://${serverHost}:${port}/api/files/upload`;
+    if (password) {
+      url += `?password=${encodeURIComponent(password)}`;
+    }
+
+    const formData = new FormData();
+    const blob = new Blob([fileBuffer]);
+    formData.append('file', blob, fileName);
+    if (remotePath) {
+      formData.append('path', remotePath);
+    }
+
+    const response = await fetch(url, {
+      method: 'POST',
+      body: formData,
+    });
+
+    if (!response.ok) {
+      throw new Error(`Upload failed: ${response.statusText}`);
+    }
+
+    return { success: true };
+  } catch (error: any) {
+    log.error('Remote upload failed:', error);
+    return { success: false, error: error.message };
+  }
+});
+
+ipcMain.handle('remote-download-file', async (_event, serverHost: string, port: number, fileName: string, remotePath: string, password?: string) => {
+  try {
+    const win = electronState.getMainWindow();
+    if (!win) {
+      throw new Error('No window found');
+    }
+
+    let url = `http://${serverHost}:${port}/api/files/${encodeURIComponent(fileName)}`;
+    if (password) {
+      url += `?password=${encodeURIComponent(password)}`;
+    }
+
+    const response = await fetch(url);
+    if (!response.ok) {
+      throw new Error(`Download failed: ${response.statusText}`);
+    }
+
+    const buffer = await response.arrayBuffer();
+
+    const { filePath } = await dialog.showSaveDialog(win, {
+      title: '保存文件',
+      defaultPath: fileName,
+    });
+
+    if (!filePath) {
+      return { success: false, canceled: true };
+    }
+
+    fs.writeFileSync(filePath, Buffer.from(buffer));
+
+    return { success: true, filePath };
+  } catch (error: any) {
+    log.error('Remote download failed:', error);
+    return { success: false, error: error.message };
+  }
+});
+
 async function startServer() {
   if (electronState.isDevelopment()) {
     log.info('In dev mode, assuming external servers are running.');