Function load_policy_from_reader 

pub fn load_policy_from_reader(
    read: &(dyn Fn(&[u8]) -> Result<Option<Vec<u8>>, StorageError> + '_),
    tenant: TenantId,
    cap: u64,
) -> Result<Option<ActivePolicy>, AuthzError>

Policy loader over an injected key-reader. Used by the coordinator’s commit-time revalidation so it never opens a nested store view (which would deadlock under the store’s publish lock).

Errors

Propagates reader failures and returns AuthzError::InvalidPolicy when stored metadata is malformed or uses the removed global policy layout.