Function resolve_overlay 

pub fn resolve_overlay(
    parent: &Manifest,
    overlay: &Value,
) -> Result<Manifest, ManifestError>

Apply an arbitrary sparse overlay onto parent — the shared core of both shipped-profile (resolve) and local-profile (registry) resolution. Serializes the parent to a [Value], leaf-replace-merges the overlay, re-deserializes, drops the profile catalogue from the resolved view, then re-runs the manifest invariants and the tighten-only consent floor.

Errors: a parse error if the merge produces an invalid manifest, or a validation error if the merged manifest breaks an invariant or loosens a consent floor.