-- Which of the sidebar's fixed headings a person has folded away.
--
-- A project group already carries `collapsed` on its own row, and the reasoning
-- there applies here too: folding a heading is a statement about the work, not
-- about the screen. "I am not in Etiketter at the moment" is as true on the laptop
-- as on the desktop, which is what separates this from the sidebar's *width* —
-- that one is in localStorage, because a narrow laptop and a wide monitor deserve
-- different answers and syncing it would make one of them wrong every time you
-- moved.
--
-- A JSON array of keys rather than a column per heading. The set is the sidebar's
-- to decide and it has already changed twice; a column each would mean a migration
-- every time a heading is added, and a row full of booleans nobody reads for the
-- ones that were removed. Unknown keys are ignored on the way out, so an old
-- client's folded state survives a heading being renamed rather than resetting it.
ALTER TABLE users ADD COLUMN sidebar_collapsed TEXT NOT NULL DEFAULT '[]';