* feat: implement silent payment derivation paths and master HD wallet integration
- Added default derivation paths for silent payments (mainnet and testnet).
- Introduced `_masterHD` for handling seed-based key derivations.
- Updated silent payment address record to include spend derivation path.
- Refactored UTXO handling and scanning logic to support multiple receivers with unique derivation paths.
- Improved logging for better debugging of silent payment workflows.
* refactor: remove debug prints