Function try_recast_from_cache 

pub fn try_recast_from_cache(
    canonical: &Path,
    output: &Path,
    dtype: GGMLType,
    redownload: bool,
) -> Result<bool>

Return the canonical cache path, recasting from cache when present.

Returns true when the caller can return early (cache hit already recast to output), false when the caller must download + convert. Thin wrapper over zsfm_hub::try_recast_from_cache so CLI + Python share one implementation.