Testing React bindings

Create a fresh memory-backed engine and clock per test, wrap the component in FatigueProvider, then trigger the user action.

const clock = { now: () => 0 }
const fatigue = createFatigue({ storage: memoryAdapter(), clock })
render(<FatigueProvider value={fatigue}><Coupon /></FatigueProvider>)
await user.click(screen.getByRole('button'))

Assert visible state and optionally fatigue.exportRecord(key). Wrap with <StrictMode> to catch render-time side effects. For SSR coverage, render to string then hydrate with equivalent initial records and assert there are no mismatch warnings. Direct core writes do not notify hook subscribers; use hook actions for reactive tests.