`flex: none` stops the `+n` box shrinking but not its text wrapping, so a
row too narrow for title + separator + suffix broke the one-line summary in
the exact case the slot exists for. Add `white-space: nowrap` and pin the
declaration as CSS text, since jsdom has no layout.
Also align the README's row illustration with the English rendering (the
same sentence's plan-strip clause already used it), and record the two
deferred review findings in the Agent Note so they survive merge.
9b01da195a