Function blast_radius_for_project 

pub fn blast_radius_for_project(
    project_dir: &Path,
    node: &str,
) -> Result<BlastRadius, String>

Compute the warble::BlastRadius of node in a Warble project’s bound wren project. Resolves the project the same way compile_project_to_ir does (profile.yml → context binding → wren project → MdlContext), but stops short of a full compile — just the lineage query.