feat: v0.9.0 — single-screen 3-pane shell + left Assets pane (wallet/reputation/fleet/time controls) from a single /api/state poll; right pane placeholder

lib/useGameState.test.ts

@@ -0,0 +1,39 @@
+import { afterEach, describe, expect, it, vi } from 'vitest';
+import { fetchState } from './useGameState';
+
+// The hook's fetch logic (lib/useGameState.ts) against a mocked global fetch — the polling
+// loop itself is plain setInterval and covered by e2e (panes.spec.ts renders from it).
+
+const SNAPSHOT = {
+  account: { cash: 20_000, reputation: 10 },
+  simState: { clockMs: 1_750_000_000_000, timeScale: 1, paused: false },
+  planes: [],
+  contracts: [],
+};
+
+afterEach(() => {
+  vi.unstubAllGlobals();
+});
+
+describe('fetchState', () => {
+  it('GETs /api/state with no-store and returns the parsed snapshot on success', async () => {
+    const fetchMock = vi.fn(async () => ({ ok: true, status: 200, json: async () => SNAPSHOT }));
+    vi.stubGlobal('fetch', fetchMock);
+
+    await expect(fetchState()).resolves.toEqual(SNAPSHOT);
+    expect(fetchMock).toHaveBeenCalledTimes(1);
+    expect(fetchMock).toHaveBeenCalledWith('/api/state', { cache: 'no-store' });
+  });
+
+  it('throws with the HTTP status on a non-2xx response', async () => {
+    vi.stubGlobal('fetch', vi.fn(async () => ({ ok: false, status: 500, json: async () => ({}) })));
+    await expect(fetchState()).rejects.toThrow('GET /api/state → HTTP 500');
+  });
+
+  it('throws on a network failure (no response at all)', async () => {
+    vi.stubGlobal('fetch', vi.fn(async () => {
+      throw new Error('fetch failed');
+    }));
+    await expect(fetchState()).rejects.toThrow('fetch failed');
+  });
+});