feat(autocomplete): add responsive detached mode

[FabienMotte]

Summary

This PR adds a responsive detached mode to the Autocomplete widget for mobile devices. When a configurable media query matches (default: max-width: 680px), the inline search input is replaced with a search button that opens a full-screen overlay with the search form and results panel.

• New detachedMediaQuery option to control when detached mode activates (set to "" to disable)
• New translations option for detached mode UI text (cancel button, search button title, clear button title)
• Two layout variants: full-screen on phones, centered modal on tablets (controlled via CSS variables)
• Body scroll is locked while the overlay is open, panel stays open in detached mode
• Smooth transitions when resizing between detached and non-detached modes
• New CSS variables for overlay color, modal dimensions, and media query breakpoints
• New shared UI components: AutocompleteDetachedSearchButton, AutocompleteDetachedOverlay, AutocompleteDetachedContainer, AutocompleteDetachedFormContainer
• Refactored AutocompleteSearch (React) to accept props directly instead of using useSearchBox internally
• Updated bundle size limits, z-index layering (Chat 9998, Autocomplete 10000)
• Added common widget tests for detached mode
• Updated react/query-suggestions example with mobile-responsive layout

Result

Verified with the react/query-suggestions example (yarn start in examples/react/query-suggestions):

• Desktop (> 680px): Standard inline autocomplete with search input and dropdown panel.
• Mobile (≤ 680px): Search input is replaced by a search button. Tapping it opens a full-screen overlay with the search form, cancel button, and results panel. Tapping the overlay backdrop or pressing Cancel closes it. Submitting a query (Enter) closes the overlay and applies the search.
• Tablet / modal variant (≤ 1024px, ≥ 680px): Overlay renders as a centered modal dialog instead of full-screen.
• Resize transitions: Shrinking the viewport while the panel is open seamlessly transitions into the detached overlay. Expanding back closes the overlay and returns to inline mode.
• Scroll lock: Body scroll is prevented while the overlay is open and restored to the correct position on close.
• Clear button: The detached search button shows the current query and a clear button to reset it.
• detachedMediaQuery="": Completely disables detached mode.

All common widget tests pass for both instantsearch.js and react-instantsearch.

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Latest deployment of this branch, based on commit 3280367:

Sandbox	Source
example-instantsearch-getting-started	Configuration
example-react-instantsearch-getting-started	Configuration
example-react-instantsearch-next-app-dir-example	Configuration
example-react-instantsearch-next-routing-example	Configuration
example-vue-instantsearch-getting-started	Configuration

[Haroenv]

looks great, thanks!

[shaejaz]

Could these useEffect's be done in the ui-components? We already have the hook being passed to them (via the prop getter function I believe)