/*
 * NV-09 Back button — app/components/ui/back_button_component.rb
 *
 * A pure Ui::IconButtonComponent (F-02) with variant: :glass — the glass
 * treatment and 44px sizing already come from icon_button.css. The
 * .ui-back-button hook exists only so a future shell-specific override
 * (e.g. absolute positioning within a header) has somewhere to attach
 * without reaching into F-02's own classes.
 */