Function spawn_remote_listing 

pub fn spawn_remote_listing<F>(
    ctx: OwnedSshContext,
    remote_path: String,
    show_hidden: bool,
    sort: BrowserSort,
    send: F,
)
where
    F: FnOnce(String, String, Result<Vec<FileEntry>, String>) + Send + 'static,

Spawn background thread for remote directory listing. Sends result back via the provided sender function.