Htmx 4.0.0 has been released

Htmx 4.0.0 has been released after 8 months of development, with the major internal change being a migration from XMLHttpRequest to the fetch() API for improved simplicity and streaming HTML support. The three main user-facing changes are: attribute inheritance now requires explicit marking with `:inherited`, standardized event names, and removal of localStorage-based history support. The team is keeping version 2.x as the latest in NPM until early 2027 to avoid forcing upgrades for users relying on non-versioned CDN URLs.