The four *SortableHead islands already fall back to their sort-label record,
so B17's new `label` made the header text a third copy instead of removing the
second one — 16 redundant `children` deleted, leaving only `frescor`, which
diverges on purpose and now reads the record too.
The 3 s "safety net" timer was committing like a close, refresh included, which
recreated the per-toggle route render the 400 ms debounce was rejected for: at a
reading pace every checkbox landed outside the window. The timer now writes the
cookie only; closing repaints. A session that ends where it started refreshes
nothing, and a menu open when the route unmounts saves from the cleanup, since
Radix reports no close event for a sidebar navigation. Both pinned red first.
Also: `columnVisibility` required rather than optional for the tests' benefit,
the redundant per-list cap dropped, `resolveVisibleColumns` no longer copies,
and B29's unused `LeadershipListAccessFilter` export un-exported — knip was
failing on main too.
ed0fb4065f