Add StorageService backed by SurrealDB using the embedded RocksDB provider that persists to ./data (never in memory). Support an optional remote server via SurrealDb:RemoteUrl for frontend sync. Expose readiness and storage probe endpoints under /api/system and add a helper script to start a local SurrealDB server.
Set the backend version to 0.0.1.
Add persisted theme mode (light, dark, system) with a header menu.
Rework the light and dark palettes for stronger contrast and drop the
high-contrast theme.
Rafał Tyński