Add a module-scope Base UI toast manager bridged to the QueryClient so
every mutation can give consistent feedback. A MutationCache (extracted
into a makeQueryClient() factory for test reuse) emits a catch-all,
type-aware error toast (unless meta.suppressErrorToast) and an opt-in
success toast (meta.successMessage), reading mutation.meta + i18n.t
outside React. meta is type-checked via a react-query Register
augmentation. ToastRegion is mounted app-wide in main.tsx. Adds a toast
i18n namespace (en/sv parity) and a validated story.
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
Bootstraps the web/ SPA: Vite 6 + React 19 + TypeScript 5.8, Vitest
with jsdom, @testing-library/react, and a green smoke test asserting
the App renders its Collection heading.
Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>