Stock header experience: task-first service chrome — always-visible, visibly labeled 'Menu' trigger (mobile-menu ShowTriggerLabel) + brand on the start side, inline search affordance, account dropdown (utility trigger with a composed link-list panel), and phone CTA cluster on the end side, composed in the header shell's slots (Default pure-placeholder shell). The composition-first replacement for the deprecated field-driven Utility shell variant.

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