refactor(native): overhaul auth screens, add ModalStackHeader, and bump Expo patch releases

- Replace `Alert` with `toast` for sign-in/register errors and add a `getFormErrors` utility to extract the first Zod validation message and field set
- Display the configured server host inline on the login screen and hide the navigation header in the auth layout (`headerShown: false`, `navigationBarHidden: true`)
- Delete `AuthStackHeader` and `DetailStackHeader`; introduce `ModalStackHeader` for screens that are pushed as modals
- Remove unused `StatusBadge` component and delete unused shadcn web components (`calendar`, `drawer`)
- Bump all Expo 55 SDK packages to their latest patch versions and add `expo-web-browser` plugin to `app.json` + `@react-navigation/native` as an explicit dependency

apps/server/package.json

@@ -11,7 +11,6 @@
     "check-types": "tsc --noEmit"
   },
   "dependencies": {
-    "@orpc/client": "catalog:",
     "@orpc/contract": "catalog:",
     "@orpc/json-schema": "1.13.7",
     "@orpc/openapi": "1.13.7",