Function analyze_album_with_progress

pub fn analyze_album_with_progress<F>(
    folder: &Path,
    paths: &[PathBuf],
    options: &ScanOptions,
    threads: usize,
    on_progress: F,
) -> FolderReport
where
    F: Fn(usize, usize, &Path) + Sync,

Analyze an album while reporting each starting file to the caller.

The callback runs on an analysis worker before decoding its file, so a terminal client can show useful progress without changing ordering or requiring the core to write to a terminal itself.