fix: show login failed error message

clients/web/locales/en.json

@@ -58,6 +58,7 @@
   "hint_move": "Click a highlighted field to move a checker",
   "hint_hold_or_go": "Hold to keep points — Go to reset the setting",
   "hint_continue": "Click Continue when ready",
+  "login_failed": "Invalid username or password.",
   "sign_in": "Sign in",
   "sign_out": "Sign out",
   "create_account": "Create account",

clients/web/locales/fr.json

@@ -58,6 +58,7 @@
   "hint_move": "Cliquez un champ surligné pour déplacer",
   "hint_hold_or_go": "Tenir pour garder les points — S'en aller pour repartir",
   "hint_continue": "Cliquez Continuer quand vous êtes prêt",
+  "login_failed": "Identifiant ou mot de passe incorrect.",
   "sign_in": "Se connecter",
   "sign_out": "Se déconnecter",
   "create_account": "Créer un compte",

clients/web/src/portal/account.rs

@@ -73,7 +73,12 @@ fn LoginForm() -> impl IntoView {
                     navigate(&dest, Default::default());
                 }
                 Err(e) => {
-                    error.set(e);
+                    let msg = if e.is_empty() {
+                        t_string!(i18n, login_failed).to_string()
+                    } else {
+                        e
+                    };
+                    error.set(msg);
                     pending.set(false);
                 }
             }