A FocusSafeButton that holds the focus is disabled by aria-disabled, not the native attribute, so
every hover gated on `:disabled` / `enabled:` alone still fired on it — the glass lift, the primary /
danger / warn dim, and eight `enabled:hover:` chains (saved views, the player's list buttons, the
undo toolbar). Measured on localdev: the Pager's Next, focused at the last page, now keeps its resting
border and shadow under the pointer. The CSS selectors and the chains also exclude
`[aria-disabled="true"]`, and a lint rule refuses a bare `enabled:hover:` from now on.
- `overflow-clip` gets a safelist anchor in index.css (its only occurrence is a `.ts` constant),
and the chip-lane contract keeps it there.
- PlexPlayer's Backspace ownership rule is pinned on all three branches: nothing above, a foreign
layer above (it defers), and its own panel open under a layer (it still closes the panel).
- Removing a playlist item bumps the list's `updated_at`, like the three other item-only writes.
- Seen in a real browser on localdev: an exhausted comfort-shelf tile (an empty pinned playlist) is
focusable, aria-disabled, and its Shift+F10 menu offers Play off and Remove from shelf.