[New App] ftp/sftp client for file transfer

**Describe your feature request**:
the software look nice. but i like to also able transfer and modify files with ftp/sftp with in the application.

No files, tests, or entry points are named in the issue. Begin by locating the application's existing file-transfer or remote-connection features, then determine the scope needed for FTP/SFTP transfers and in-application file modification; done would require an agreed design and implementation covering that workflow.

由索引模型根據 Issue 內容生成。