LR-BEHAV-BG-TASKS now cites activity.list / activity.cancel and lists
every job on the stack; the import and Build Previews rows no longer
describe progress windows and toasts; a what's-new entry.
Fixes the stack not growing when tasks arrive while it already shows a
row (an egui area lays out in last frame's size, and the scroll area took
that as all the room, so later rows were cut off), and adds the Russian
"Quit Anyway".
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>