Cleaner model usage

[jpwilliams]

Summary

Moves some internals around and moves the userland APIs to be able to silently use inngest's models under the hood.

Before

const model = createAgenticOpenAiModel({
  model: openai({ model: "gpt-4" }),
  step,
});

After

// `Openai` casing matching `inngest` and other implemenations
const model = agenticOpenai({ model: "gpt-4", step });

// You can specify the usual options
const model = agenticOpenai({ model: "gpt-4", apiKey: "override", step });

// Or provide a model created elsewhere
const myCheapModel = openai({ model: "gpt-3.5-turbo" });
const model = agenticOpenai({ model: myCheapModel, step });

Also:

• Added agenticGemini()
• Moved OpenAI format parsers to a separate module