Stay informed with free updatesSimply sign up to the Artificial intelligence myFT Digest -- delivered directly to your inbox.Meta has launched its first AI model since chief executive Mark Zuckerberg led a multibillion-dollar spending spree on talent and infrastructure, in the first test of its efforts to catch up with rivals including OpenAI and Google.The $1.6tn social media platform on Wednesday unveiled Muse Spark, which it said had been “purpose-built” for use across its products.Zuckerberg...