Fix dir_browser: use default middleware_stack, enable dir_browser

Enable directory browsing with WsgiDavDirBrowser

Update app.py: Windows compatibility, parent dir auto-creation, safe delete

fix: add OPTIONS middleware with DAV header for Windows WebDAV compatibility

Upload 7 files

fix: handle None last_commit safely

fix: add support_etag and get_etag for WsgiDAV 4.3.3

fix: force Basic auth for Windows WebDAV compatibility

Add WebDAV server files