Server-side, return 200 with success: false and a friendly message when sendTestNotification reports failure (the underlying call already swallows the error); reserve real 500s for unexpected exceptions.
Client-side, teach usePost to honour the response body's success flag so success:false flips the toast to error without throwing through axios. Also tidy the toast container: drop icons, no wrapping, single-line ellipsis with a sensible max-width that hugs short messages.
- Drop the per-type icon
- Lower min-height to 40px and tighten padding
- Thin both the active progress bar and its track to 2px and pin them to the same baseline so they sit on top of each other
- Tooltip backgrounds now pull from the theme's grey palette instead of a hand-rolled blue gradient (visible bug in dark mode)
- Toast progress bars use theme.palette.primary.main so they match the rest of the brand
gorkem-bwl
Alex Holliday