key read only at call time, metered embedder) does not exist yet and is deliberately not wired: * only test doubles implement this interface. An implementation must return an embedder whose model() equals * "::" of the generation, or throw; any exception means "no embedder available" (administrator action). */ interface EmbedderFactory { /** @param array $generation a knowledge_generations row @throws \Throwable when no embedder can be built */ public function forGeneration(array $generation): Embedder; }