Expo Router v55: more native navigation, more powerful web

Expo Router v55 (part of Expo SDK 55) ships two major improvements: richer native navigation and expanded web capabilities. On the native side, a new declarative Stack API replaces the options API with composable React components for headers, search bars, and toolbars. Native Tabs now support Material Design 3 dynamic colors on Android and a bottom accessory on iOS 26. A new Color API exposes platform-specific system and dynamic colors. The Apple zoom transition API enables gesture-driven shared element transitions via the existing Link component. Experimental UISplitViewController support targets iPad. On the web side, the @expo/server package is now expo-server and ships as part of the SDK with adapters for EAS Hosting, Vercel, Netlify, Cloudflare Workers, and Bun. Custom HTTP response headers can now be defined in app config. Experimental SSR support moves beyond static-site generation to per-request HTML rendering. Experimental data loaders let you co-locate server-side data fetching with route components using a useLoaderData hook, keeping sensitive credentials server-side without separate API routes.