signHash abstract method
Signs a raw hash directly without any prefix.
Use this for:
- ERC-4337 UserOperation signing (userOpHash is already a 32-byte hash)
- Any case where you need to sign a pre-computed hash
WARNING: The hash should be exactly 32 bytes. This method does NOT add any prefix (unlike signMessage which adds EIP-191 prefix).
Implementation
Future<Uint8List> signHash(Uint8List hash);