refactor: align frontend ownership boundaries

Close audit gaps across API drift, query policy, UI, and tests.

src/pages/account/ui/components/AccountPageError.view.tsx

@@ -0,0 +1,57 @@
+import { Button } from "@mantine/core";
+import type { FC } from "react";
+import { useTranslation } from "react-i18next";
+import { Link } from "react-router";
+import { StateView } from "@/shared/ui";
+
+type AccountPageErrorProps = { code?: string; retry: () => void };
+
+const AccountPageError: FC<AccountPageErrorProps> = (props) => {
+	const { code, retry } = props;
+	const { t } = useTranslation();
+	if (code === "NOT_FOUND")
+		return (
+			<StateView
+				error
+				title={t("portfolio.accountUnavailableTitle")}
+				text={t("portfolio.accountUnavailableText")}
+				action={
+					<Button component={Link} to="/accounts">
+						{t("portfolio.back")}
+					</Button>
+				}
+			/>
+		);
+	if (code === "TBANK_NOT_CONNECTED" || code === "INVALID_TBANK_TOKEN")
+		return (
+			<StateView
+				error
+				title={t("portfolio.connectionErrorTitle")}
+				text={t("portfolio.connectionErrorText")}
+				action={
+					<Button component={Link} to="/settings">
+						{t("accounts.openSettings")}
+					</Button>
+				}
+			/>
+		);
+	if (code === "TBANK_UNAVAILABLE")
+		return (
+			<StateView
+				error
+				title={t("accounts.unavailableTitle")}
+				text={t("accounts.unavailableText")}
+				action={<Button onClick={retry}>{t("accounts.retry")}</Button>}
+			/>
+		);
+	return (
+		<StateView
+			error
+			title={t("states.errorTitle")}
+			text={t("states.errorText")}
+			action={<Button onClick={retry}>{t("accounts.retry")}</Button>}
+		/>
+	);
+};
+
+export { AccountPageError };