Domain fragment for Ash domains that extend the Diffo Provider.

Include this fragment in any domain whose resources need to participate in provider polymorphism — i.e., where belongs_to :instance, Diffo.Provider.Instance or belongs_to :party, Diffo.Provider.Party relationships must resolve via manage_relationship.

Adding this fragment causes AshNeo4j to write :Provider as an additional label on every node in the domain at CREATE time. Because AshNeo4j MATCH patterns include all node labels, Ash.get(Diffo.Provider.Instance, uuid) (which matches on [:Provider, :Instance]) will then find concrete instance nodes (e.g. ShelfInstance) that carry both :Instance (from BaseInstance) and :Provider (from this fragment).

Usage

defmodule MyApp.SRM do
  use Ash.Domain, fragments: [Diffo.Provider.DomainFragment]
  ...
end

Forgetting this is a silent footgun (no :Provider label → projection and ref resolution quietly fail), so Diffo.Provider.Extension.Verifiers.VerifyProviderDomain enforces it at compile time: a provider resource whose domain emits no :Provider label fails to compile with a message pointing here.