Add DisplayMenu component

[kualta]

Summary

Promotes the flow.game menu's triplicated big-uppercase display nav button (MenuItem copies in web/menu/src/App.tsx, RoomsPage.tsx, and the SettingsPage.tsx Back button) into the shared library as DisplayMenu / DisplayMenuItem, so the flow.game SSR rewrite can consume one canonical implementation instead of three drifting copies.

API

• DisplayMenu — <nav> wrapper, flex flex-col items-start gap-1.5, accepts all nav props.
• DisplayMenuItem — cva + useRender (same conventions as item.tsx/badge.tsx), renders a <button type="button"> by default or any element via the Base UI render prop (anchor, router Link, ...).
  • size: lg (text-2xl md:text-4xl, the rooms-page scale, default) | xl (text-6xl leading-none md:text-8xl, the home-menu scale)
  • trailing?: React.ReactNode — smaller baseline-aligned suffix (text-lg md:text-xl at lg, text-3xl md:text-4xl at xl, font-semibold text-muted-foreground), used for the Play preload percentage
  • disabled?: boolean — sets aria-disabled + data-disabled, native disabled when rendering the default <button>, swaps cursor-pointer hover:text-muted-foreground for cursor-default
  • base: uppercase, font-bold tracking-tight text-foreground, transition-[color] duration-200 ease-(--ease-out)
  • data-slot="display-menu" / "display-menu-item" / "display-menu-item-trailing"; displayMenuItemVariants exported alongside the components
• Exported from src/components/ui/index.ts; version bumped 0.16.1 -> 0.17.0 per the component-add convention (add StatusWidget component #7).

Testing

• bun run lint and bun run typecheck are both clean.
• bun run dev -> Components page -> new "Display Menu" section at the bottom demos xl with a trailing 42% while disabled, default lg items, an anchor via render, and a disabled lg item (no hover shift, default cursor).