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/features/auth/ui/AuthForm/AuthForm.test.tsx

@@ -30,4 +30,44 @@ describe("AuthForm", () => {
 		await waitFor(() => expect(onSubmit).not.toHaveBeenCalled());
 		expect(await screen.findByText("Пароли не совпадают")).toBeInTheDocument();
 	});
+
+	it.each([
+		["register", "Регистрация", "Уже есть аккаунт? Войти"],
+		["login", "Вход", "Нет аккаунта? Зарегистрироваться"],
+	])("blocks the switch-auth link while %s is submitting", async (_mode, submitLabel, linkLabel) => {
+		const { promise, resolve } = Promise.withResolvers<void>();
+		const onSubmit = vi.fn(() => promise);
+		render(
+			<MantineProvider>
+				<MemoryRouter>
+					<AuthForm
+						onSubmit={onSubmit}
+						register={_mode === "register"}
+					/>
+				</MemoryRouter>
+			</MantineProvider>,
+		);
+
+		fireEvent.change(screen.getByLabelText("Email"), {
+			target: { value: "user@example.com" },
+		});
+		fireEvent.change(screen.getByLabelText("Пароль"), {
+			target: { value: "a secure password" },
+		});
+
+		if (_mode === "register") {
+			fireEvent.change(screen.getByLabelText("Подтвердите пароль"), {
+				target: { value: "a secure password" },
+			});
+		}
+
+		fireEvent.click(screen.getByRole("button", { name: submitLabel }));
+
+		await waitFor(() => expect(onSubmit).toHaveBeenCalled());
+		expect(screen.queryByRole("link", { name: linkLabel })).not.toBeInTheDocument();
+		expect(screen.getByRole("button", { name: linkLabel })).toBeDisabled();
+
+		resolve();
+		await screen.findByRole("link", { name: linkLabel });
+	});
 });