Payment Method Tile

Client component: it holds the selected method in useState and tells the controlled mode from the uncontrolled one by comparing method with undefined, so the file carries "use client". The group is built as a real role="radiogroup" with role="radio" on every tile: Tab enters the group once, and from there the arrows walk the options through a roving tabindex (tabIndex 0 on the selected one, -1 on the rest) — this is the native behaviour of <input type="radio">, implemented by hand. The selected option is marked by two cues at once — a border and a checkmark in the corner — because the fill colour alone does not read under a colour vision deficiency. On a narrow container the tiles fold into a single column and unfold back into a row. The palette has been moved to light-dark(): in the dark branch the tile border is lighter than its background. The method names and hints are exposed through the methodTitle and methodHint props with Russian defaults, and the group's surface is set by the background prop and is absent by default.