feat(js/ai): Adds "restart" for tool interrupts with flexible resuming.

[mbleigh]

Implements "restarts" on top of interrupts. Usage:

const sendText = ai.defineTool({
  name: 'sendText',
  description: 'send a text message',
  inputSchema: z.object({to: z.array(z.string()), message: z.string()}),
}, async (input, {context, interrupt, resumed}) => {
  // if not confirmed
  if (!resumed) interrupt({message: "Does this text look good to send?");
  sendTextMessage(context.auth.uid, input);
});

let response = await ai.generate({
  prompt: "Send a text to mom telling her I'll be late.",
  tools: [sendText],
});

if (interrupts.length) {
  const revisedMessage = await confirmOrReviseMessage(interrupts['0]);
  response = await ai.generate({
    resume: {restart: sendText.restart(interrupts[0], true, {replaceInput: revisedMessage});
  });
}

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

[mbleigh]

This is ready for review, the build errors are unrelated to my code.

[pavelgj]

restart and resume are used interchangeably... should probably be consistent to avoid confusion. Maybe call it restartMetadata? and restarted?

[mbleigh]

I made the tool API (input, {interrupt, resumed}) because (input, {interrupt, restarted}) doesn't really feel as nice...but maybe it's fine?

Another option could be going back to the original confirm and make the argument confirmed. (Then we could have resume + complete + confirm?)

I think restart may still be the most accurate tho...