Chat improvements to citations, navigation and more

A few updates to chat that make it easier to find, faster to explore, and more connected to your data.

Chat in the sidebar—chat is now a first-class item in the global navigation, sitting alongside Search and New. Click Chat any time to open your full-page chat without hunting through menus or relying on the corner peek.

Video autoplay in highlights—when chat returns video highlights, clicking one now plays it and automatically advances through the rest of the reel. You can still click any individual video citation to jump straight to that clip; autoplay only kicks in from the highlights carousel.

Collapsible conversation history—the sidebar in full-page chat can now be collapsed to give your conversation more room. Click the toggle to hide the history list when you don't need it, and bring it back whenever you want to switch conversations.

Source previews—hovering on a citation now shows a source card, and clicking it opens the source directly as a peek overlay without navigating away. Data entries and Docs open right over the conversation so you can verify the context and come straight back. Sources are also shown as inline links below each response, so you can see at a glance where the answer came from.