RAG component does not expose providerMetadata to usageHandler

[yantakus]

For example, Agent component with the following config:

export const titleAgent = new Agent(components.agent, {
  languageModel: "openai/gpt-4o-mini",
  usageHandler: async (ctx, args) => {
    const gateway = args.providerMetadata?.gateway;
    if (!gateway) {
      throw new Error("Missing providerMetadata.gateway");
    }
    const creditsSpent = costToCredits(gateway.cost);
    ...
  };
});

works just fine.

And RAG component with the same config (it only has an additional textEmbeddingModel: "openai/text-embedding-3-small") throws an error because args.providerMetadata is missing.

Please, add it, otherwise I have to calculate the cost myself. Not a big deal, but still would like not to hardcode input and output token cost.