In the long human search for tools that feel less like machines and more like companions, Meta has introduced Charm — a keychain-sized device designed to make artificial intelligence as portable and instinctive as a house key. Unveiled by Mark Zuckerberg at Meta Connect in Menlo Park, the gadget carries a 2-inch touchscreen, 5G connectivity, and a conversational AI assistant into a form factor smaller than most wallets. It arrives in December, at a price yet to be named, as the technology industry collectively wonders what kind of object will define the era after the smartphone.