Meta Platforms Inc. on Wednesday launched $1,299 virtual-reality glasses that undercut Apple Inc. in price and size while putting its headset line on track for profitability.The new device, called Meta VR Glasses, represents a significant shift in headset design. Its processor, cooling fan, battery and other computing components are housed in an external pack that can clip to a user’s pocket or rest on a table. Meta’s previous models incorporated those components into the headset itself, while A...