fix(auth,bank): guard switch-auth nav and surface banking retry

AuthForm disables the switch-auth Link while submit is pending so pointer
click and Enter can no longer leave the auth route and lose the draft/error
context. The form restores a true Link after the request settles.

CardsPage/CardPage distinguish cold vs cached banking failures:
- cold card/section errors expose accessible alert + retry
- cached failures keep the previous data and offer a section GET retry
- summary-only/history-only outages do not hide successful sections
- notFound still skips the retry CTA

Tests cover the pending link guard, cold/cached cards error with retry,
summary failure with retry, and the prerequisite card list recovery.

Closes #56, #57

src/pages/cards/ui/CardsPage/CardsPage.test.tsx

@@ -47,8 +47,9 @@ function renderCards(isFail = false, hasCategoryFailure = false) {
 		),
 	);
 
-	return render(
-		<QueryClientProvider client={createTestQueryClient()}>
+	const client = createTestQueryClient();
+	render(
+		<QueryClientProvider client={client}>
 			<MantineProvider env="test">
 				<MemoryRouter initialEntries={["/cards?month=2026-09"]}>
 					<CardsPage />
@@ -56,6 +57,8 @@ function renderCards(isFail = false, hasCategoryFailure = false) {
 			</MantineProvider>
 		</QueryClientProvider>,
 	);
+
+	return client;
 }
 
 describe("CardsPage", () => {
@@ -232,4 +235,76 @@ describe("CardsPage", () => {
 		});
 		expect(screen.queryByRole("alert")).not.toBeInTheDocument();
 	});
+
+	it("shows a cold cards error with retry", async () => {
+		renderCards(true);
+
+		expect(
+			await screen.findByRole("alert", {}, { timeout: 5000 }),
+		).toHaveTextContent("Не удалось загрузить данные карт.");
+		expect(
+			screen.getByRole("button", { name: "Повторить" }),
+		).toBeInTheDocument();
+
+		server.use(
+			http.get("*/api/v1/bank-cards", () =>
+				HttpResponse.json([
+					{
+						archivedAt: null,
+						balance: money("10000"),
+						bankName: null,
+						id: "a",
+						lastFour: null,
+						name: "Повседневная",
+						openingBalance: money("10000"),
+						openingDate: "2026-01-01",
+						version: 1,
+					},
+				]),
+			),
+		);
+		fireEvent.click(screen.getByRole("button", { name: "Повторить" }));
+
+		await waitFor(() =>
+			expect(screen.queryByRole("alert")).not.toBeInTheDocument(),
+		);
+		expect(
+			screen.getByRole("link", { name: /Повседневная/ }),
+		).toBeInTheDocument();
+	});
+
+	it("shows a cached cards error while keeping the grid", async () => {
+		const view = renderCards();
+
+		await screen.findByRole("heading", { name: "Добавьте первую карту" });
+		server.use(
+			http.get("*/api/v1/bank-cards", () =>
+				HttpResponse.json([
+					{
+						archivedAt: null,
+						balance: money("10000"),
+						bankName: null,
+						id: "a",
+						lastFour: null,
+						name: "Повседневная",
+						openingBalance: money("10000"),
+						openingDate: "2026-01-01",
+						version: 1,
+					},
+				]),
+			),
+		);
+		await view.invalidateQueries();
+		await screen.findByRole("link", { name: /Повседневная/ });
+
+		server.use(http.get("*/api/v1/bank-cards", () => HttpResponse.error()));
+		await view.invalidateQueries();
+
+		expect(
+			await screen.findByRole("alert", {}, { timeout: 5000 }),
+		).toHaveTextContent("Не удалось обновить данные. Показаны последние полученные.");
+		expect(
+			screen.getByRole("link", { name: /Повседневная/ }),
+		).toBeInTheDocument();
+	});
 });