fix: preserve cached data during refresh failures

src/features/auth/model/auth.test.tsx

@@ -34,4 +34,58 @@ describe("AuthProvider", () => {
 
 		expect(authorization).toBe("Bearer restored-token");
 	});
+
+	it("settles unauthenticated and clears cached data when cold-start refresh has a transport error", async () => {
+		server.use(http.post("*/api/v1/auth/refresh", () => HttpResponse.error()));
+		const queryClient = new QueryClient();
+		queryClient.setQueryData(["cached-query"], { value: "stale" });
+		const wrapper = ({ children }: { children: ReactNode }) => (
+			<QueryClientProvider client={queryClient}>
+				<AuthProvider>{children}</AuthProvider>
+			</QueryClientProvider>
+		);
+		const { result } = renderHook(() => useAuth(), { wrapper });
+
+		await waitFor(() => expect(result.current.ready).toBe(true));
+
+		expect(result.current.user).toBeNull();
+		expect(result.current.accessToken).toBeNull();
+		expect(queryClient.getQueryData(["cached-query"])).toBeUndefined();
+	});
+
+	it("keeps the original protected 401 when serialized refresh has a transport error", async () => {
+		let refreshCalls = 0;
+		server.use(
+			http.post("*/api/v1/auth/refresh", () => {
+				refreshCalls += 1;
+				return refreshCalls === 1
+					? HttpResponse.json({
+							accessToken: "restored-token",
+							user: { id: "user-1", email: "user@example.com" },
+						})
+					: HttpResponse.error();
+			}),
+			http.get("*/api/v1/brokerage-accounts", () =>
+				HttpResponse.json({ code: "UNAUTHORIZED" }, { status: 401 }),
+			),
+		);
+		const queryClient = new QueryClient();
+		queryClient.setQueryData(["cached-query"], { value: "stale" });
+		const wrapper = ({ children }: { children: ReactNode }) => (
+			<QueryClientProvider client={queryClient}>
+				<AuthProvider>{children}</AuthProvider>
+			</QueryClientProvider>
+		);
+		const { result } = renderHook(() => useAuth(), { wrapper });
+
+		await waitFor(() =>
+			expect(result.current.accessToken).toBe("restored-token"),
+		);
+		const response = await apiClient.GET("/api/v1/brokerage-accounts");
+
+		expect(response.response.status).toBe(401);
+		await waitFor(() => expect(result.current.user).toBeNull());
+		expect(result.current.accessToken).toBeNull();
+		expect(queryClient.getQueryData(["cached-query"])).toBeUndefined();
+	});
 });