Function resolve_model_source_with_product_sources 

pub async fn resolve_model_source_with_product_sources(
    model: &str,
    cache_dir: &Path,
    download: DownloadPolicy,
    autosize: Option<(AutoSizeProfile, f32)>,
    source_args: &ProductSourceArgs,
) -> Result<Resolved>

Resolve one physical model and then replace only the explicitly selected semantic/tokenizer roles. This keeps the positional MODEL as the sole weight source while allowing quantized checkpoints to consume canonical base-model semantics without a model-name mapping or hidden environment.