Thread page navigation and unread handling

The thread page now loads more intelligently and helps you keep track of what you haven't read yet.

Unread-first loading

When you open a thread, the page loads the newest unread content first, rather than loading everything from the start. A "Load earlier" button lets you pull in older content on demand. This makes long-running threads open much faster.

When new activity arrives while you're reading, a banner appears offering to load the updates without losing your scroll position.

A navigation bar at the top of the thread page now includes links to jump to the first unread item, the latest activity, and the poll (if there is one). This saves scrolling in long threads.

New activity highlighting

New comments and activity are marked with a "New" indicator the first time you see them. Once read, the indicator disappears. Previously, the indicator could appear on content you'd already seen.