fix(toast-load): infinite load of adding a card on a collection page
Adding a card from a collection page shows 'Adding card...' forever. The collection page's `<Suspense>` boundary re-suspends on query invalidation, unmounting the component before React Query can fire the mutate-level `onSuccess`/`onError` callbacks that update the toast.
Moved toast handling from mutate-level callbacks into definition-level callbacks on `useMutation`, which always fire regardless of component mount state.