perf(tbank-connection): poll screen sync every five seconds

During active screen sync, status checks and observe reads run every 5s
instead of 1s; terminal state observes resources immediately.
OpenSpec change: WealthLedger/specs#21

src/features/tbank-connection/model/screen-sync.test.tsx

@@ -420,7 +420,7 @@ describe("page-owned screen synchronization", () => {
 	it.each(["leave", "logout"])(
 		"publishes completed empty coverage while history runs, then stops on %s",
 		async (boundary) => {
-			vi.useFakeTimers({ toFake: ["Date"] });
+			vi.useFakeTimers();
 
 			try {
 				auth();
@@ -429,15 +429,13 @@ describe("page-owned screen synchronization", () => {
 				const modes: (null | string)[] = [];
 
 				const snapshot = () =>
-					resource(
-						isCompleted
-							? []
-							: null,
-						{
-							dataRevision: isCompleted ? "covered" : "initial",
-							sync: { errorCode: null, id: "history", state: "running" },
-						},
-					);
+					resource(isCompleted ? [] : null, {
+						dataRevision: isCompleted ? "covered" : "initial",
+						sync: { errorCode: null, id: "history", state: "running" },
+						unavailableReason: isCompleted
+							? undefined
+							: "CALENDAR_OR_ACCOUNT_HISTORY",
+					});
 
 				server.use(
 					http.get("*/api/v1/brokerage-accounts", ({ request }) => {
@@ -472,31 +470,26 @@ describe("page-owned screen synchronization", () => {
 					{ wrapper: createQueryWrapper().wrapper },
 				);
 
-				await waitFor(() =>
-					expect(result.current.accounts.meta?.sync.id).toBe("history"),
-				);
-				await waitFor(() => expect(polls).toBeGreaterThan(0));
+				await vi.waitFor(() => expect(modes).toEqual([null, "observe"]));
+				expect(polls).toBe(1);
 				expect(result.current.sync.refreshing).toBe(true);
 				expect(result.current.accounts.data).toBeUndefined();
-				isCompleted = true;
-				vi.setSystemTime(Date.now() + 61_000);
-				await waitFor(() => expect(result.current.accounts.data).toEqual([]), {
-					timeout: 3000,
-				});
-				expect(result.current.sync.refreshing).toBe(true);
-				await act(async () => {
-					await new Promise(resolve => setTimeout(resolve, 1100));
-				});
 
-				expect(modes[0]).toBeNull();
-				expect(modes.slice(1).every(mode => mode === "observe")).toBe(true);
+				isCompleted = true;
+				await act(() => vi.advanceTimersByTimeAsync(5000));
+				await vi.waitFor(() =>
+					expect(result.current.accounts.data).toEqual([]),
+				);
+
+				expect(result.current.sync.refreshing).toBe(true);
+				expect(modes).toEqual([null, "observe", "observe"]);
+
 				if (boundary === "leave") unmount();
 				else act(() => configureAuthClient());
-				const stopped = polls;
-				await act(async () => {
-					await new Promise(resolve => setTimeout(resolve, 1100));
-				});
-				expect(polls).toBe(stopped);
+
+				await act(() => vi.advanceTimersByTimeAsync(60_000));
+				expect(polls).toBe(2);
+				expect(modes).toHaveLength(3);
 			}
 			finally {
 				vi.useRealTimers();
@@ -504,6 +497,144 @@ describe("page-owned screen synchronization", () => {
 		},
 	);
 
+	it("runs the next status poll and observe read only after five seconds", async () => {
+		auth();
+		const modes: (null | string)[] = [];
+		const pollGaps: number[] = [];
+		let polls = 0;
+		let previousPollAt = 0;
+
+		server.use(
+			http.get("*/api/v1/brokerage-accounts", ({ request }) => {
+				modes.push(new URL(request.url).searchParams.get("sync"));
+
+				return HttpResponse.json(
+					resource([], {
+						sync: { errorCode: null, id: "history", state: "running" },
+					}),
+				);
+			}),
+			http.get("*/api/v1/tbank-sync/:id", () => {
+				const now = Date.now();
+				if (previousPollAt) pollGaps.push(now - previousPollAt);
+				previousPollAt = now;
+				polls++;
+
+				return HttpResponse.json({
+					errorCode: null,
+					id: "history",
+					now: "2026-09-25T00:00:00Z",
+					scope: null,
+					state: "running",
+				});
+			}),
+		);
+
+		vi.useFakeTimers();
+
+		try {
+			const { unmount } = renderHook(
+				() => {
+					const accounts = useBrokerageAccounts();
+
+					return {
+						accounts,
+						sync: useScreenSync({ screen: "accounts" }, [accounts]),
+					};
+				},
+				{ wrapper: createQueryWrapper().wrapper },
+			);
+
+			await vi.waitFor(() => expect(modes).toEqual([null, "observe"]));
+			expect(polls).toBe(1);
+
+			await act(() => vi.advanceTimersByTimeAsync(2500));
+			expect(polls).toBe(1);
+			expect(modes).toEqual([null, "observe"]);
+
+			await act(() => vi.advanceTimersByTimeAsync(5000));
+			await vi.waitFor(() => expect(polls).toBe(2));
+
+			expect(modes).toEqual([null, "observe", "observe"]);
+			expect(pollGaps).toHaveLength(1);
+			expect(pollGaps[0]).toBeGreaterThanOrEqual(5000);
+
+			unmount();
+			await act(() => vi.advanceTimersByTimeAsync(60_000));
+			expect(polls).toBe(2);
+			expect(modes).toHaveLength(3);
+		}
+		finally {
+			vi.useRealTimers();
+		}
+	});
+	it("observes resources immediately when a status response turns terminal", async () => {
+		auth();
+		const modes: (null | string)[] = [];
+		let isCompleted = false;
+		let polls = 0;
+
+		const meta = () =>
+			resource([], {
+				dataRevision: isCompleted ? "covered" : "initial",
+				sync: { errorCode: null, id: "history", state: "running" },
+			});
+
+		server.use(
+			http.get("*/api/v1/brokerage-accounts", ({ request }) => {
+				modes.push(new URL(request.url).searchParams.get("sync"));
+
+				return HttpResponse.json(meta());
+			}),
+			http.get("*/api/v1/tbank-sync/:id", () => {
+				polls++;
+
+				return HttpResponse.json({
+					errorCode: null,
+					id: "history",
+					now: "2026-09-25T00:00:00Z",
+					scope: null,
+					state: isCompleted ? "succeeded" : "running",
+				});
+			}),
+		);
+
+		vi.useFakeTimers();
+
+		try {
+			const { result } = renderHook(
+				() => {
+					const accounts = useBrokerageAccounts();
+
+					return {
+						accounts,
+						sync: useScreenSync({ screen: "accounts" }, [accounts]),
+					};
+				},
+				{ wrapper: createQueryWrapper().wrapper },
+			);
+
+			await vi.waitFor(() => expect(modes).toEqual([null, "observe"]));
+			expect(polls).toBe(1);
+			expect(result.current.sync.refreshing).toBe(true);
+
+			isCompleted = true;
+			await act(() => vi.advanceTimersByTimeAsync(5000));
+			await vi.waitFor(() => expect(modes).toEqual([null, "observe", "observe"]));
+
+			expect(polls).toBe(2);
+			expect(result.current.accounts.meta?.dataRevision).toBe("covered");
+			expect(result.current.sync.refreshing).toBe(false);
+
+			await act(() => vi.advanceTimersByTimeAsync(60_000));
+			expect(polls).toBe(2);
+			expect(modes).toHaveLength(3);
+		}
+		finally {
+			vi.useRealTimers();
+		}
+	});
+
 	it("clears private snapshots when status confirms access loss", async () => {
 		auth();
 		server.use(