feat: chat with Meta AI

[alpersamur3]

What

Adds client.sendMetaAiMessage(prompt, options?) — send a prompt to Meta AI and receive its reply as a Message (text or media).

Why

The library could already @-mention Meta AI in groups (invokedBotWid), but there was no way to hold a 1:1 conversation with Meta AI and get the answer back. This adds a first-class method for it.

How

• Meta AI only replies when the outgoing message carries a bot secret, so the method generates messageSecret + botMessageSecret (via WAWebBotMessageSecret.genBotMsgSecretFromMsgSecret) and attaches them.
• The text reply streams in as a single message edited in place until its final chunk (botEditType reaches last, or full for a one-shot answer). A generated image arrives as a separate message right after, so the method waits for a finished reply plus a short quiet period and returns the media message when one is produced.
• Returns a Message, so both text and generated images flow through the existing Message API (downloadMedia, etc.). options.timeout (default 60000 ms) caps the wait.

Usage

const reply = await client.sendMetaAiMessage('What is WhatsApp? Answer in one sentence.');
console.log(reply.body);

// "generate an image ..." prompts come back as an image message
if (reply.hasMedia) {
    const media = await reply.downloadMedia();
}

Notes

Meta AI availability is region-gated by WhatsApp; where available this works even when the web UI entry point is hidden.

Tested

Verified against a live session:

• Text: "2+2?" → "Dört", capital-of-country prompts → "Ankara" / "Paris".
• Image: "generate an image of a car" → an image message; downloadMedia() returns the JPEG (~255 KB).
• Multi-sentence answers stream and resolve fully.