[AINews] OpenAI 2026 DevDay：多新特性发布 ChatGPT周活达12亿

[AINews] OpenAI DevDay 2026: Dots, 6.1 Sol, Ultrafast, Decisions API, Agents API, Spaces, Marketplace, and 1.2 Billion ChatGPT WAU

这是迄今信心最足的一届DevDay。