feat: window.ai support

[transmissions11]

Describe the solution you'd like
Allow users to log in via https://windowai.io/

If they have the extension installed, just use it and don't prompt for API key or show the input, otherwise work as normal.

[transmissions11]

https://www.npmjs.com/package/window.ai

[nmandal]

I've been looking into this and found some good hooks using Wanda that abstract a lot of the extension checking. Perhaps the APIKeyModal component could be refactored to choose either windowai or bring your own key.

[nmandal]

An additional question I have here for this effort is what models is Flux looking to support with the window.ai effort? Presently, the models supported are:

export enum ModelID {
  GPT3 = "openai/gpt3.5",
  GPT4 = "openai/gpt4",
  Together = "together/gpt-neoxt-20B",
  Cohere = "cohere/xlarge"
  // local
}