fix(login): show toast for non-401 errors on sgID profile

apps/frontend/src/features/login/LoginPage.tsx

@@ -114,8 +114,13 @@ export const LoginPage = (): JSX.Element => {
         return t('features.login.LoginPage.forbidden')
       case StatusCodes.UNAUTHORIZED.toString():
         return t('features.login.LoginPage.expiredSession')
-      default:
+      default: {
+        const code = parseInt(statusCode ?? '')
+        if (code >= 500 && code < 600) {
+          return t('features.common.errors.serverError')
+        }
         return t('features.common.errors.generic')
+      }
     }
   }, [statusCode])
 

apps/frontend/src/features/login/SelectProfilePage.tsx

@@ -29,7 +29,7 @@ import { DASHBOARD_ROUTE, LOGIN_ROUTE } from '~constants/routes'
 import { useIsMobile } from '~hooks/useIsMobile'
 import { useLocalStorage } from '~hooks/useLocalStorage'
 import { useToast } from '~hooks/useToast'
-import { ApiService } from '~services/ApiService'
+import { ApiService, HttpError } from '~services/ApiService'
 import Button from '~components/Button'
 import { ModalCloseButton } from '~components/Modal'
 
@@ -132,7 +132,21 @@ export const SelectProfilePage = (): JSX.Element => {
   // If redirected back here but already authed, redirect to dashboard.
   if (user) window.location.replace(DASHBOARD_ROUTE)
   // User doesn't have any profiles, should reattempt to login
-  if (profilesResponse.error) window.location.replace(LOGIN_ROUTE)
+
+  if (profilesResponse.error) {
+    const err = profilesResponse.error
+    const statusCode = err instanceof HttpError ? err.code : undefined
+
+    if (statusCode === StatusCodes.UNAUTHORIZED) {
+      // 401 — session invalid, redirect quietly
+      window.location.replace(LOGIN_ROUTE)
+    } else {
+      // all other HTTP errors — redirect with status so LoginPage can surface the appropriate toast.
+      // For non-HTTP errors (e.g. network failures), use a non-5xx sentinel so we fall back to the generic toast.
+      const statusParam = statusCode ?? 0
+      window.location.replace(`${LOGIN_ROUTE}?status=${statusParam}`)
+    }
+  }
 
   useEffect(() => {
     if (profilesResponse.data?.profiles.length === 0) {

apps/frontend/src/i18n/locales/features/common/en-sg.ts

@@ -62,6 +62,7 @@ export const enSG: Common = {
     },
     pageNotFound: 'This page could not be found.',
     generic: 'Something went wrong. Please try again later.',
+    serverError: 'A server error occurred. Please try again later.',
   },
   tooltip: {
     deleteField: 'Delete field',

apps/frontend/src/i18n/locales/features/common/index.ts

@@ -62,6 +62,7 @@ export interface Common {
     }
     pageNotFound: string
     generic: string
+    serverError: string
   }
   tooltip: {
     deleteField: string