- Consolidate settings, tasks, and audit storage into SettingsStore and SecretStore
- Implement PersistentWriteFailure for detailed error reporting across storage scopes
- Migrate secret retrieval to rely primarily on reference-based lookups
- Add ThemeMode persistence and AccountSyncState serialization
- Modernize SecureConfigStore with clear path resolution and support for UI state
- Streamline Rust build process by migrating from custom scripts to Makefile
- Remove redundant build_rust_ffi.sh and update integration scripts