The description hover card loses its two hand-managed timers and its fixed `bottom`
anchor. It now opens above the title through the platform, which means `flip` can rescue
it when there is no room up there either — the old fixed anchor could only grow upward.
Its width moves from a px clamp to a rem one, so it follows the font-scale slider like
the rest of the app.
Add-to-playlist is no longer disabled in the player's true fullscreen: its menu rides
the platform, which portals into the fullscreen element rather than <body>. The download
button stays hidden there on purpose — it opens a Modal, and Modal still portals to
<body>, so its dialog would open invisibly. Lifting that needs the same fullscreen-aware
root inside Modal.
NOT migrated, deliberately: PlexPlayer's gear and tracks panels. They are the one place
where portalling would be a visual regression — the control bar sits inside the player's
`transform: scale(1.25)` windowed subtree, so a panel portaled out of it renders at 80%
of the surrounding UI's size. Positioning would still be correct (floating-ui reads
post-transform viewport rects); the panel's own type and padding would not. Doing this
properly means either portalling into that scaled wrapper or dropping the scale, and
either way it needs a UAT with a playing video that this environment cannot run.
Verified in-browser: the description card opens after its hover-intent delay, anchored
8px above the title and left-aligned to it, with the description loaded.