The app already finds an installed font for CJK (and other) characters
the UI fonts lack, the first time a frame paints one (ui_fonts): reading
a system CJK font at every startup duplicated that, cost a font file's
read and memory for interfaces that never show CJK, and broke its test.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>