The archived worktrees button now acts as a toggle — clicking it while already viewing archived worktrees returns to the previously selected worktree, matching the toggle behavior of Canvas/Shelf. Changes: - Add preArchivedWorktreeID to state to remember selection before entering archived view - Convert selectArchivedWorktrees action into a toggle: exit restores previous worktree - Button icon changes from archivebox → arrow.uturn.left when in archived view - Menu/button labels dynamically switch between 'Archived Worktrees' and 'Exit Archived Worktrees' - Update existing tests to expect preArchivedWorktreeID - Add new test for toggle-exit behavior Signed-off-by: Alex <alex.tech.lab@outlook.com>