feat(js/ai): adds defineInterrupt for more ergonomic interrupts

[mbleigh]

const askQuestion = ai.defineInterrupt({
  name: 'askQuestion',
  description: "Ask a multiple choice question of the user.",
  inputSchema: z.object({choices: z.array(z.string()), allowOther: z.boolean().optional().describe('set to true to allow a write-in response in addition to any choices supplied')}),
  replySchema: z.string(),
  requestMetadata: {note: "This is a question."}
});

will result in a toolRequest like:

{
  toolRequest:  {
    name: "askQuestion",
    input: {choices: [...]},
    metadata: {interrupt: {note: "This is a question."}}
  }
}

See also Discord thread for additional work I'm planning to do.

Checklist (if applicable):

• PR title is following https://www.conventionalcommits.org/en/v1.0.0/
• Tested (manually, unit tested, etc.)
• Docs bug: [Docs] Document Interrupts #1657 1657