fix: surface notification test failures cleanly instead of as 500s

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.

client/src/App.tsx

@@ -33,11 +33,14 @@ function App() {
 						body: {
 							backgroundColor: theme.palette.background.default,
 						},
-						".Toastify__progress-bar, .Toastify__progress-bar--bg": {
+						".Toastify__progress-bar": {
 							height: 2,
 							bottom: 0,
 							top: "auto",
 						},
+						".Toastify__progress-bar--bg": {
+							display: "none",
+						},
 					}}
 				/>
 				<AppLayout>
@@ -53,9 +56,15 @@ function App() {
 							"--toastify-color-progress-dark": theme.palette.primary.main,
 							"--toastify-toast-min-height": "40px",
 							"--toastify-toast-padding": "8px 12px",
+							"--toastify-toast-width": "auto",
 						} as CSSProperties
 					}
-					toastStyle={{ minHeight: 40, padding: "8px 12px" }}
+					toastStyle={{
+						minHeight: 40,
+						padding: "8px 12px",
+						width: "auto",
+						maxWidth: "min(560px, calc(100vw - 32px))",
+					}}
 					progressStyle={{ height: 2 }}
 				/>
 			</ThemeProvider>

client/src/Hooks/UseApi.ts

@@ -57,7 +57,11 @@ export const usePost = <B = any, R = any>() => {
 					...config?.headers,
 				},
 			});
-			toastSuccess(res.data?.msg || "Operation successful");
+			if (res.data?.success === false) {
+				toastError(res.data?.msg || "Operation failed");
+			} else {
+				toastSuccess(res.data?.msg || "Operation successful");
+			}
 
 			return res.data;
 		} catch (err: any) {

client/src/Hooks/UseToast.ts

@@ -4,8 +4,9 @@ export const useToast = () => {
 	const showToast = (message: string, options?: ToastOptions) => {
 		toast.dismiss();
 		const baseStyle: React.CSSProperties = {
-			whiteSpace: "pre-line",
-			wordBreak: "break-word",
+			whiteSpace: "nowrap",
+			overflow: "hidden",
+			textOverflow: "ellipsis",
 		};
 		toast(message, {
 			...options,

server/src/controllers/notificationController.ts

@@ -37,13 +37,9 @@ class NotificationController implements INotificationController {
 			const notification = testNotificationBodyValidation.parse(req.body);
 			const success = await this.notificationsService.sendTestNotification(notification);
 
-			if (!success) {
-				throw new AppError({ message: "Sending notification failed", status: 500 });
-			}
-
 			return res.status(200).json({
-				success: true,
-				msg: "Notification sent successfully",
+				success,
+				msg: success ? "Notification sent successfully" : "Notification could not be sent — check the destination details.",
 				details: { service: SERVICE_NAME },
 			});
 		} catch (error) {