Function reconstruct_graph_from_node_modules 

pub fn reconstruct_graph_from_node_modules(
    project_root: &Path,
) -> Option<DependencyGraph>

Attempt to reconstruct a dependency graph from an existing node_modules/.dnx directory.

Reads node_modules/.dnx/packages.json and each package’s package.json to rebuild the DependencyGraph locally, avoiding a full network resolve.

Returns None if the dnx directory or manifest doesn’t exist.