Task_toggling_a_skill_auto_saves_selection waited a hard 500 ms for a
debounced save. It passed in isolation and in either half of the suite,
but failed in a full run: this batch added three DB-backed UI test
classes whose real SQLite contexts load the thread pool enough that the
timer callback misses the window. Product code is unchanged.
Same assertion, polled with a 5 s deadline - the pattern the newly added
DetailsIsland/TasksIsland tests already use.