fix(admin): classify bulk wallet adjustment failures

apps/aether-gateway/src/state/testing.rs

@@ -480,6 +480,11 @@ impl AppState {
         self
     }
 
+    pub(crate) fn fail_auth_wallet_lookup_for_tests(mut self, user_id: impl Into<String>) -> Self {
+        self.auth_wallet_lookup_error_for_tests = Some(user_id.into());
+        self
+    }
+
     pub(crate) fn with_admin_wallet_payment_orders_for_tests<I>(mut self, orders: I) -> Self
     where
         I: IntoIterator<Item = crate::AdminWalletPaymentOrderRecord>,