One feature: the Playground now streams.
New
- Streaming Playground responses for every model (#942). Previously only fusion streamed — an ordinary chat blocked until the whole completion arrived. Now every send streams: tokens render as they arrive, reasoning models show their thinking as a collapsible trace inside the bubble (it lands together with the first answer token, since the gateway holds a stream's preamble until the attempt commits and can still fail over), and auto-scroll follows the stream only while you're at the bottom — scrolling up to read is respected, sending re-engages it. Mid-stream provider errors keep the partial answer and append an error bubble. Verified end to end in a real browser against a mock streaming provider.