File library expands to Free and Go users, with storage management

File library now available to Free and Go users, including EEA users. Users can add recent files from the composer, browse saved files in Library, and ask ChatGPT about previously uploaded files. Storage management introduced with limits: Free (500 MB), Go (4 GB), Plus and Business (20 GB), Pro (100 GB). Generated images continue to appear in Images tab. Available on web with Library and Recent files supported on web, iOS, and Android.