Stock header experience: thin utility strip (language switcher + utility links) over the main logo/nav/CTA bar, composed in the header shell's slots (Default pure-placeholder shell — the desktop utility row is the thin top strip). The composition-first counterpart of the field-driven TwoTier shell variant.

• src/components/registry/experiences/partial-designs/header-two-tier/header-two-tier.tsx→components/registry/experiences/partial-designs/header-two-tier/header-two-tier.tsx
• src/components/registry/experiences/partial-designs/header-two-tier/header-two-tier.recipe.ts→src/recipes/header-two-tier.recipe.ts