- pkg/protocol/nwc/wallet.go
- Implemented `WalletService` with method registration and request handling.
- Added default stub handlers for supported wallet methods.
- Included support for notifications with `SendNotification`.
- pkg/protocol/nwc/client-methods.go
- Added `Subscribe` function for handling client subscriptions.
- cmd/walletcli/mock-wallet-service/main.go
- Implemented a mock CLI tool for wallet service.
- Added command-line flags for relay connection and key management.
- Added handlers for various wallet service methods (e.g., `GetInfo`, `GetBalance`, etc.).
- pkg/protocol/nwc/types.go
- Added `GetWalletServiceInfo` to the list of wallet service capabilities.
