With `Places|Italy|Rome` on the selected photos, the boxes of `Places`
and `Italy` were empty: a folded keyword gave no sign that something in
it was applied.
A keyword whose own box is empty now carries a dot in it when the
selection has a keyword inside it, at any depth, and the box's tooltip
names what is inside ("Inside: Rome, Venice", four by name, then a
count). The tick and the dash stay about the keyword itself and come
first: a keyword the photos have themselves shows that, not the dot. A
click on the box does what it did.
What is inside each keyword is worked out with the ticks, once per
selection (`Ticks::inside`), not per row and frame.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
