Function resolve_output_path 

pub fn resolve_output_path(
    input: &Path,
    input_dir: &Path,
    output_dir: &Path,
    suffix: Option<&str>,
    format_ext: Option<&str>,
) -> PathBuf

Resolve the output path for a processed image.

Mirrors the subdirectory structure from input_dir into output_dir, appends an optional suffix before the extension, and overrides the extension when format_ext is provided. Raw-format inputs default to .jpg when no explicit format is given.