feat: integrate nuc EIP-712 signer support

[tim-hm]

Goal

Update the nuc-ts library to take advantage of EIP-712 signing. This will require exposing configuration options to the user — or potentially detecting the environment.

Action items

• upgrade nuc-ts when EIP-712 support lands (feat: support crypto wallet signers (EIP-712) nuc-ts#78)
• add user-facing configuration options to enable EIP-712 signing
• pass the provided singer through to the nuc lib

Acceptance Criteria

• A consumer can successfully initialise the library with a (metamask) EIP-712 signer.
• All operations that require NUC creation correctly use the new signing flow.