Optimizing Zustand Persistence with Custom Storage and Rehydration

Act as a Frontend Performance and Security Engineer. Configure Zustand's powerful `persist` middleware specifically for a massive, high-traffic e-commerce application. You are forbidden from using standard LocalStorage; you must implement a custom [STORAGE_ENGINE] (e.g., asynchronous IndexedDB via `idb-keyval` or a highly secure encrypted storage wrapper). Implement a strict `partialize` filter function to ensure absolutely only the [PARTIALIZE_KEYS] (e.g., `cartItems`, `theme`) are written to disk, keeping the I/O storage footprint microscopic. Crucially, architect a robust [VERSION_MIGRATION_STRATEGY] (`migrate` function) capable of flawlessly handling complex state schema changes between continuous app deployments without destroying the user's active session or crashing the app.