The picker was hidden outright at 54px, on the grounds that a combo box there
could only show a stub of a name. True, but it left the collapsed rail with no
way to change project at all — and the audit page's own inventory of the 11
collapsible controls says the rail's fold "giữ nguyên toàn bộ".
A folder QToolButton stands in for it: same items, and choosing one moves the
combo, so _on_rail_project_pick stays the single code path. Its tooltip carries
the current project name, which the combo could not have shown anyway. It
matches the ＋ button's width and drops its menu arrow — at 42px the arrow
would take a third of the row to say nothing.
check_nav now collapses the rail and requires a reachable picker whose menu
matches the combo item for item, then picks a row and asserts the project
actually changed. Hiding the button fails it.
15/15 checkers pass.
Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
