Reproduce:
1. Add an item with animations, and play them.
2. Remove the item.
3. Add it back.
4. Observe the button shows up in "Paused" state, even though it's playing.
This is because the server-side template wasn't doing anything to try to keep the play/pause button it renders in sync with the current saved state in the cookies, so it was always causing a morph to the pause state. Now we listen to the cookie instead!
I also updated the JS behavior to be a bit more consistent: treat the behavior as defaulting to true, unless it's explicitly set to the string "false".
Rather than surface the fact that pose and style are independent values, in this change we treat them as basically mutually exclusive appearance options.
If there's no alt style selected, a pose option is visibly selected instead. If there's an alt style selected, no pose option is visibly selected (even though the data model contains one), and selecting one removes the alt style.
Note that these queries are a bit slow. I don't think these new subpages will be accessed anywhere near often enough for their ~2sec query time to be a big deal. But if we start getting into trouble with it (e.g. someone starts slamming us for fun), we can look into how how cache these values over time.
Just a small visual cleanup because I happened to click on item trades
today! We don't need to repeat "This Week" a million times. Just output
it for the first row, then hide it for the following. (We still include
it in screen reader output for semantic clarity; this is just a visual
cleanup.)
