The selected row carries selection-background-color, so a checkmark repeats
what the colour says — and in a combo as wide as "VN" it repeated it on top of
the letters. A combo's default delegate paints menu-style, which is where the
glyph comes from; a plain QStyledItemDelegate paints item-view style, which has
none. widen_popup does both jobs now, so it is tidy_popup.
check_combo_popup additionally requires the delegate to be the plain one and the
stylesheet to still tint the current row — removing the delegate line fails it.
21/21 checkers pass.
Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
