Release Notes for Safari Technology Preview 239

Safari Technology Preview 239 is now available for macOS Tahoe and macOS Sequoia. This release brings one CSS new feature (`:open` pseudo-class for `<input>` elements) and a Web Inspector enhancement adding color contrast info to the Color Picker. Bug fixes span accessibility (VoiceOver issues with aria-owned rows, splitter elements, aria-labelledby geometry), CSS layout (collapsed borders, subgrid sizing, baseline calculation, percentage heights in intrinsic-sized containers), editing (execCommand FormatBlock, text-indent flickering), forms (readonly date input bypass), MathML rendering, media (VideoFrame color range, PDF dark mode), scrolling (scroll anchoring causing blank pages or negative offsets), Web API (change/dragend events), Web Inspector (Network panel, multi-node Copy HTML), WebAssembly streaming compilation, and WebRTC (RTCPeerConnection.addIceCandidate rejection).