Migrate Combobox from Polaris React

Combobox has no supported Polaris web component equivalent. Keep the Polaris React component during an incremental migration.

Don't present an s-text-field and s-popover composition as an equivalent migration. Combobox owns coordinated focus, keyboard navigation, active-option semantics, selection, dismissal, and assistive-technology behavior that a visual approximation doesn't preserve.

If the application must remove Polaris React before a supported replacement exists, treat the work as a custom accessible widget rather than a component migration. Implement and test the complete ARIA combobox pattern for the application's interaction model.

Anchor to Remove Polaris ReactRemove Polaris React

Don't remove @shopify/polaris while a Combobox call site remains. Remove the package only after those call sites have a supported replacement or a separately reviewed custom implementation.