Switch to "lingui" for better DX.
Tried to persist existing languages as much as possible.
Removed "vite-plugin-node-polyfills" because it's incompatible with "lingui"
With 12ef012e4b this has no benefit anymore, because the app now always checks if authentication is enabled by the server first before any other request can be sent.
* Add dynamic subpath support for WebUI
- Add SubpathConfig utility for server-side subpath detection
- Configure React Router basename from server config
- Update API base URL handling for subpath compatibility
- Fix asset loading with relative paths
- Add VITE_SUBPATH environment variable for development
- Update locales and manifest paths for subpath support
Closes#174
* Move VITE_SUBPATH interface to vite-env.d.ts
* Ensure production bundle always uses relative base
